How To Grow Cauliflower In Aquaponics

Aquaponics is a growth industry that is easily available to every level of experience for the avid aquaculturist, whether their goal is to set up a gargantuan commercial farm, to start up a small to medium size going concern to supply at the local market, or simply to grow a few veggies at the bottom of the garden to feed the family.

Tomatoes, potatoes, grapes, onions are just a small selection of crops that can be reared under this system, but there is also a very wide variety of leafy plants that can be cultivated under the farming initiative that is aquaponics.

One of those is cauliflower. Underappreciated, it is loaded with essential nutrients, flourishes within the aquaponics environment, and is gaining in popularity.

Why Cauliflowers In Aquaponics?

Growing cauliflowers in aquaponics is a comfortable and sustainable way to grow this vegetable in a controlled environment that promotes faster growing times, resulting in a more frequent harvest of an often-overlooked vegetable that itself has a wide variety of uses for many a tasty dish.

The botanical family that the cauliflower belongs to is called Brassicaceae, and its siblings are cabbage, broccoli, kale, and brussels sprouts. What differentiates it from its brothers and sisters are the cream-colored stems that it is renowned for.

This compact head, known as the curd, is packed full of vitamins and minerals as well as being loaded with fiber and antioxidants. The white coloration is due to an insufficient quantity of a substance called chlorophyll, which is the cause of the green pigment in plants.

In nature, there are many types of pigments yet Chlorophyll alone is the key to photosynthesis. What this process does is allows plants to absorb sunlight and carbon dioxide efficiently, naturally, and then to convert those rays of light into energy, which finally releases oxygen into the air to sustain life on earth.

Despite the white stems on the head of the cauliflower, it contains more than enough chlorophyll to provide all the benefits derived from this molecule. For example, eating this vegetable can aid in reducing inflammation and the risks of cancer due to its anti-carcinogenic properties, and it even has a natural deodorant that helps with bad breath.

What is not widely known about cauliflowers is that there are actually over 100 varieties, which can be broken down into four main categories: Italian, Northwest European, Asian and Northern European.

Historically, the Italian cauliflower is the mother of all cauliflowers, the other varieties derived from this original. The Northern European variant became popular in the 18th century in Germany while the Northwest European cauliflower flourished a while later in the 19th century in France.

Unlike the two European varieties that take longer to bring to full maturity, the Asian offshoot has a more flexible resilience that enables it to grow in warmer temperatures with an added bonus that it stands up well to weather fluctuations.

Fortunately, the climate in an aquaponics farm is controlled and remains consistent. Under these circumstances, the choice of which cauliflower to plant is down to personal choice, goals, and local availability.

The Practical Way To Grow Cauliflowers in Aquaponics

To grow cauliflower in aquaponics several stages have to be followed, with certain considerations factored into the equation from the outset to make a success of the project.

First, the seeds need to be selected with care and close attention. Genetic manipulation is common with cauliflower seeds to create a hybrid vegetable, and that alteration can produce a resulting harvest that is different than what was expected.

About 10 years ago cauliflowers with different colored curds started to appear, orange, green, purple, to name a few, and soon became quite popular, adding a splash of color to the kitchen table without altering the traditional taste significantly and only marginally affecting the nutritional values.

Hybrid cauliflowers have no different discernable taste to the traditional cream-colored head variety, fortunately, but the hybrids do need to be planted from new every year.

Therefore, it is imperative to ensure that the seeds purchased are open-pollinated, meaning that they have not been altered scientifically in any way and that they have been fertilized by bees, moths, and birds, for example. Aquaponics is all about mimicking nature so it’s always better if the seeds and plants are as close to natural as possible.

To start, newly purchased seeds are in an elongated pod and are only ready to be harvested from the pod when it turns brown. That indicates that they are now mature and ready to be stored in a dark place temporarily before being sowed into a growing medium where they will reside for between 4 to 5 weeks to complete the slow germination process.

Proper watering and care are important to promote optimum growth and guarantee healthy seedlings. When the germination process is completed, they will then be ready for transplantation into a permanent growing medium.

In aquaponics, choosing the media bed is crucial so there is a good movement with the flooding and draining system employed to encourage the roots to expand outwards, especially since cauliflower is a heavy plant. Expanded clay pebbles are probably the most versatile media to use, allowing enough air and moisture for the needs of this vegetable.

Fortunately, cauliflowers need very little maintenance and, being a water-based plant, are one of the best vegetables to grow for beginners as they easily thrive in the aquaponics world.

Also, being a fairly easy and hardy vegetable to grow, it is possible to speed up the formation of the heads of the cauliflower by reducing the air temperature range down to between 50 to 59° from its normal range of between 66 to 77° for autumn crops; for spring crops that air temperature range can be elevated to between 59 to 68°.

If the temperature is too cold, or the cauliflowers do not receive at least 6 hours of sunlight per day, either directly or from grow lamps, the heads will not properly mature. Overexposure to sunlight, on the other hand, can adversely affect the harvest by causing the curd to separate into rice-like grains, so care has to be taken.

That same amount of care has to be allocated to the choice of fish due to these specific temperature ranges that can be too cold for some species of fish. One of the best varieties to complement cauliflowers in aquaponics is trout as they do well in cooler water temperatures, and will supply all the nutritional needs of the burgeoning aquaponics vegetable garden.

Afterward, when some of the fish have matured and outgrown their surroundings, some of the trout can be harvested themselves to provide a very healthy meal, being a good source of protein and loaded as they are with omega 3s.

When initially setting up the growing system for cauliflowers in aquaponics, it is important that the water temperature is monitored constantly and that the nutrient demands are met. Cauliflowers react favorably to high levels of nitrogen and phosphorus so nitrate levels also have to be kept and the correct levels.

With a commercial farm that has other vegetables apart from cauliflowers, separation has to be adhered to in regards to nutrient hungry plants if they are grouped together, as supplying the nutritional needs of all of them in the same zone can be challenging.

However, with proper initial planning, and an efficient system put in place, growing cauliflowers in aquaponics can be very rewarding with a regular harvest possible every few months despite the seasons and surrounding weather conditions.

The Blanching Of Cauliflowers

Once the head of the cauliflower achieves a diameter of about 1 – 2 inches, the outer leaves need to be tied together over the expanding head of the plant. An elastic band or a piece of twine is sufficient for this task, as long as a certain amount of flexibility is left to allow for further growth of the head and leaves.

This technique is known as blanching and if overlooked the traditional cream color of the curd can be lost, turning it into a not-so-attractive greenish-brown color instead. Not only will it appear unpalatable to the eye, but the taste will become stronger and very bitter as well.

Blanching is not necessary from day one, but about 30 days after transplanting the seedlings it is advisable to start checking the development of the head. When the curd is about the size of a chicken egg, the process of blanching can begin.

Conduct tying the leaves loosely over the head at this stage to allow leeway so the head can grow freely without being constricted by the leaves. After that, continued regular attention needs to be paid to all the plants as the heads on different cauliflowers will expand at varying growth spurts even if they were all transplanted at the same time.

Using different colored elastic bands can aid in differentiating which plants are ready for harvesting and which need a few more days to further mature.

This process is slightly time-consuming, but it is 100% worthwhile to take this extra step to ensure that the head forms perfectly and, more importantly, has that sweet taste that you’re striving for.

Amazingly, thanks to dedicated plant breeders, there are some varieties of cauliflowers that perform self-blanching so the leaves do not need to be tied manually over the growing curds. This time-consuming endeavor undertaken by the plant itself relieves the farmer of this burden, with the leaves curling over the developing head automatically as it continues to grow.

In about twelve weeks, when the heads are compact and firm, they will reach full maturity and be ready to harvest. The indicator that the cauliflower is ready is when the head is firm, white, and compact. Excise the head with a knife, taking care not to damage the leaves, and enjoy.

The Benefits Of Cauliflower In An Aquaponic Garden

A fact about the humble cauliflowers that is easily overlooked when compared to other, more popular trending vegetables, is just how healthy they can be. Studies have shown that obesity can be tackled by introducing this vegetable that is packed with fiber into your regular diet. It also has a wealth of other nutrients and a single serving of 100g contains:

  • Vitamin C – 24.7mg
  • Dietary Fiber – 2g
  • Calcium – 24mg
  • Phosphorus – 44mg
  • Potassium – 299mg
  • Zinc – 0.27mg
  • Copper – 0.039mg
  • Manganese – 0.155mg
  • Selenium – 0.6µg
  • Fluoride – 1µg
  • Vitamin B-6 – 0.184mg
  • Folate- 57µg
  • Choline – 44.3mg

An extra bonus is that these vegetables are low in carbohydrates. That makes them even more attractive from an aquaponics farmer’s point of view, with the cauliflower being featured worldwide as a replacement for high carbohydrate foods in popular dishes or even as a complete replacement item to healthify a staple meal.

Innovative ingredients are popping up all over the internet on how to make cauliflower rice, soups, pizzas, and many other healthy food items suitable for the popular keto diet.

Aquaponics And The Sustainable Cauliflower

As a farming method for raising fish and growing vegetables, it is hard to find a system that is better than aquaponics. It has the potential to be able to feed the world in a sustainable way that can be adopted and transported to virtually any country in the world, to the four corners of the earth.

This form of farming is becoming universally popular with individuals, business people, entrepreneurs, and even governments, all impressed by the substantially increased food production capabilities within a controlled, indoor environment that uses less water, requires less land, and has reduced labor needs compared to traditional outdoor farming.

Furthermore, the resulting harvests, devoid of pesticides and chemical fertilizers, have a tendency to produce crops that provide better nutritional benefits, a bonus in countries where affordable nutritional foods are in short supply. Accompanied by the fish as a source of protein and it’s plain to see how aquaponics can feed the world.

The wide range of produce that can be grown in aquaponics is incredible. Cauliflowers can be reared under the same umbrella as peppers, tomatoes, cucumbers, beets, and even tropical fruits such as bananas, oranges, and lemons to add a wider range to the harvest

This recirculating enclosed aquaculture that spawns a better cauliflower, combined with the raising of fish, can provide nutritious food to feed a family or a village in any type of climate, hot or cold, dry or wet for the foreseeable future.

Can You Use Snails In Aquaponics?

With an aquaponics venture, a symbiotic agreement exists between the crops being grown and the fish in a connected tank, each washing the hand of the other, so to speak.

This closed system is extremely efficient, is beneficial for both organisms, and pays dividends for the farmer in the form of better crops and healthier fish. Into this harmonious environment, would it be wise or advisable to add a third living component in the form of snails?

Easily overlooked and flying under the radar, the humble snail is not immediately considered as a potentially important addition that would have anything to add to an already efficient aquaponics bio-sphere. But that couldn’t be further from the truth, the benefits being surprisingly numerous.

Aquaponics With Snails

The work that snails undertake in aquaponics can be compared to the work done by worms in soil. Earthworms by their nature increase nutrient availability, boost drainage efficiency, and improves the structural stability of the soil, and that in turn enhances the productivity of the farm, making a happy farmer.

Snails are the worms in aquaponics and can be just as beneficial, if not more so. They act as an early warning system to emerging problems as well as having a natural instinct to keep a clean house.

That’s not to say that fish are messy aquarium mates, but sometimes uneaten excess food can find its way to the bottom of the tank, stay there and start to rot. That decaying food matter can adversely affect the well-balanced ecosystem if not continually removed on a regular maintenance routine.

Snails are similar to auto cleaners and whatever excess food falls to the bottom of the tank is disposed of in short order.

And talking of eating. If the fish are not being fed sufficiently, they will, like any other creature, search for another source of food. That search will quickly lead to the snails and will put them squarely in the center of the new menu.

It may seem a bit harsh but in the role of natural selection, and the hierarchy of the aquaponics farm, the fish are ranked as more important in the system than the snails. Once the feeding level for the fish is back to normal, they will, fortunately, return to their normal diet and cease snacking on the snails.

Conversely, this situation can work the other way, but not in a survival of the fittest way.

This generally occurs if a dead fish goes unnoticed by the farmer, which is easily done in a vibrant underwater environment and, just like decaying food, the body will start to rot on the floor of the tank, which in turn will raise the ammonia to a toxic level.

Being prolific eaters with insatiable appetites, snails will gravitate towards any dead fish and the remains will be gone in a matter of days, restoring the delicate balance.

How Are Snails Important In Aquaponics?

With a bustling farming endeavor, it can be a relatively easy matter to either overfeed or underfeed the fish in aquaponics, to treat them just like a component in the closed-circuit system rather than a living, breathing organism, and not prioritize their nutritional needs.

In both events, the snails can be an early indicator of what is happening in the fish tank in regards to the well-being of the aquatic livestock. Due to their presence overfeeding can be quickly recognized as, when there is an overabundance of food, the snails eat more and tend to breed more, multiplying rapidly in just a few weeks.

So, it is a clear indication when there is a sudden snail population explosion that too much food is being allocated to the fish, who, unlike the snails who hoover up any excess with wanton abandon, only eat until they are satiated.

The reverse can be noticed if the fish start to snack on their slow-moving tank mates. If one morning all the snails are gone, leaving behind only empty shells, then the fish are definitely not being fed sufficiently. Once noticed, and before it gets to the complete decimation stage, adjustments can be made accordingly.

Not only are snails a good barometer of proper feeding levels, but they can also be a reliable indicator of the quality of the water. If, for example, there is a very low level of oxygen available to adequately sustain life or if there is some other problem, the snails will decide it’s time to find a better environment and head towards the exit, and the edge of the tank.

It is not necessary to be a snail whisperer to interpret what they are trying to communicate from their clustered position at the lip of the aquarium – they want out. Their positioning can indicate a whole range of problems, but more importantly, it is an early warning klaxon that something is going wrong.

Once noticed, the exact problem needs to be identified and a quick solution found before the situation worsens and jeopardizes the entire aquaponics farm, risking the loss of fish life and the loss of a valuable harvest.

Types of Snails for Aquaponics

It is important, however, to choose the right snails from the outset, as not all snails are suitably efficient for aquaponics.

Two that fit the bill are the Malaysian trumpet snails and Ramshorn snails. Out of the two, the Ramshorn snail is the preferred option for aquaponics, acting as an early warning system, keeping the fish tank free from decaying matter, and in the eventuality that the fish are underfed, they can be a readily available food source.

Their ability to breed faster than the Malaysian trumpet snail is one of the things that sets them apart. The lifespan of a snail is generally about one year, although in some cases that can extend to between 2 to 3 years, so it is beneficial if they can reproduce quickly to keep the population at a good level.

Adding snails into an aquarium enhances the underwater environment by simple diversification. Apart from the aforementioned benefits they bring to the aquarium, incorporating another species such as snails adds another dimension of enjoyment and splashes of slow-moving intricate colors and unusual shapes.

They tend to be compatible co-inhabitants to most species of fish and, even though some species can over-reproduce rapidly if left to their own devices unmonitored, they can make interesting pets in and of themselves.

In-depth research is required before introducing even one snail into the tank to prepare yourself for their needs and in expectation of the changes they are going to bring, which can be both positive and negative if overlooked.

On occasion, an over-abundance of snails can enter the aquarium by hitching rides on plants, in gravel or even on decorations as minute transparent eggs. And before you know what’s happening, there are dozens of snails that have not been accounted for, negatively affecting the finely tuned system and creating an imbalance.

To combat this over-population and strain on the filtration system, some of the snails would have to be removed. Yet even this can be a challenge in itself as they are very adept at hide-and-seek. An interesting method of tracking them down and eliminating them is to send in a snail to catch a snail.

This solution calls for a type of snail that eats other snails. Once in the aquarium, these Assassin snails being carnivores will set to work straight away to reduce the over-population and re-balance the equilibrium that was initially strived for.

An Aquaponic Snail’s Pace

Choosing the correct and right quantity of snails for your aquaponics farm can expand the efficiency of the farm. They can alleviate the need for constant surveillance and be an early warning system for the little, unseen problems that can easily be overlooked, and become major problems.

Incorporate them, treat them as well as you do the fish, as a valuable member of the aquarium. You will be amazed at how the humble snail can make your life easier, and how it will slow the hectic pace that comes with a high- maintenance aquaponics project right down to a snail’s pace.

Do Fish Need Light in Aquaponics?

When building an aquaponics system, you’ll already know the direct link between plants and fish and how they both require each other to survive. Light is essential for plant growth, yet many new growers are not sure about their fish’s position.

Do fish need light in aquaponics? Even though plants need sunshine, fish like to have some shade. While fish don’t need sunlight to grow and thrive, they need periods of light and darkness like fish in an aquarium. Without changes in day or night periods, many fish can become sluggish, sick, or stop eating. Based on where your aquaponic system is, you’ll need to provide your fish with light, be it artificial or indirect sunlight, daily.

Why Fish Need Light in an Aquaponics System?

Fish only need light so they can see their food, yet there are newer studies showing light delivers additional advantages for your fish.

Aquatic animals are light sensitive by nature, and based on studies, fish productivity, activity, and overall health may be affected by light intensity, wavelength, and duration.

Some light types control temperature and can be suitable substitutes for heaters. So, if you live in colder climates, it allows you to raise fish used to thrive in warmer climates, such as tilapia.

Adding artificial light to your aquaponic fish tank can help with egg development and health, as well as helping avoid stress and poor health.

Choosing Light for Your Fish

One thing you will find is whether you have an indoor aquaponics system or an outdoor one. If your garden is outdoor, you may not need additional lighting since you can use daylight and night.

However, if your garden is undercover or indoors where light is potentially limited, you could require such additional lighting. You may need light, yet you will need to make sure it is the right light for your fish.

LED Light

Although on the newer end of the scale, it is recommended to use LED lights if possible. They cost more upfront, yet they can easily be adjusted, and there is little heat output. The significant advantage with LED lighting systems is they are far cheaper to run than alternatives.

Incandescent and Fluorescent Lighting 

Incandescent and fluorescent lamps are other types of lights that can be used as well. However, these forms have minimal functionality, and it is not possible to change the strength or temperature of the light.

If you plan to use these, do so with extra caution, as they can lead to abnormal light-induced responses like your fish being too aggressive to each other. Heat problems caused by these types of lights may also influence the health of your fish.

Light Distribution

The light distribution also needs consideration, so it covers all your tanks rather than just part of it. This is truer should there be any heat output from your lights, as it could cause warm and cold spots. 

Lighting Periods for Aquaponic Fish Tanks

You will never leave your light on around the clock as this would give the impression of permanent light and doing so would have severe effects on the health of your fish.

Besides fish health, you could find an increase in the number of algae that grows in your system. Once you have an influx in your system, it can begin consuming nutrients meant for your plants and your fish. One area that would be affected is the amount of oxygen available in the water for your fish.

The best way to control this is by using a timer for your lighting system. You use one already for your water pump, so adding another for your lights wouldn’t be an issue.

Aquaponic System Requirements

Knowing that you should have a period of nighttime for your fish to rest, it is handy to understand the other areas of your system at the same time.

Here’s a quick breakdown of other vital areas for your fish and every area of your aquaponic garden.

Water Source

Water is among the most critical areas of your entire system. Both your plants and your fish rely on it to survive.

When you first build your system, you will cycle it, so the water is suitable for your fish and plants. However, over time, you need to top up this water to counteract the effects of evaporation and use of your system.

You have many options available, yet many gardeners use regular tap for this. It is okay to use this rather than harvested rainwater, yet you must understand your municipal water.

You would need a separate tank for this use where you fill it with tap water and mix in some ascorbic acid; let this sit for a couple of days so the ascorbic acid will self-neutralize. It needs this second tank because you can’t put chloraminated water or ascorbic acid into a live aquaponics system.

Water Temperature

The water temperature can be affected through your lighting, although it would cool again when lights are not used. Tilapia, Bass, Goldfish, and Catfish are good examples, and like warmer water with temperatures of 65° to 85°F. Fish such as Trout are cold water and thrive in ranges of 55° to 65°F.

Both kinds of fish can be affected if water temperatures are too warm or too cold.

Water pH Levels

Your lights and the temperature can lead to changes in your water’s pH levels. In your system, you will see changes if ammonia rises from your fish or when you add water to top up the levels.

You must monitor the pH levels as often as you can, so you have a good understanding of what they are and how they stand against the ideal levels of a pH at 6.8 to 7.4.

Oxygen for Fish

Most fish are happy when they have dissolved oxygen ranges 5-12 mg/L. If they are too low, and your fish suffer. You could find fish stress, have stunted growth, and probable death.

Oxygen depletion can occur through heat from the summer or through your lighting. The design of many aquaponics systems can introduce dissolved oxygen by the crashing of return water. However, it doesn’t hurt to use an air pump and air stone to be safe.

Oxygen for Plants

When you use gravel in your flood and drain system, this offers near-perfect oxygen levels getting to the roots of your crops. However, there will still be oxygen in the water they absorb, which would have an impact if it weren’t present in the ideal volume.

Conclusion

With the above, you can see that while it is good to have some light for fish, you need to be sure that this light may not generate heat.

The type of fish you have is powerful dictators to lights that heat or not, as is the growth of algae. You will get algae growth from sunlight hitting the water, and you would need to make sure no light gets in the side of your tank.

Since fish don’t like direct light, only introduce moderate light, and make sure they have a dark period for 8 hours as a minimum.

Do Fish Breed in Aquaponics?

When gardeners build their systems, they often do this to grow vegetables and fish to eat. While they fully understand the vegetable side of things, they may not be fully aware of the fish’s side. Sometimes, this leads to the question.

Do fish breed in aquaponics? You will find a handful of fish that are suitable for aquaponics, and along with this, not all fish breed in captivity. Some species breed quickly, which causes issues with overstocking and could lead to a separate breeding tank for the protection of the small fish.   

Fish Care in Aquaponics

Fish rely on the water where they live, and any sudden changes can affect health and well-being. If you have fish species that can breed, they will only do so in ideal conditions.

Many changes in your system’s conditions can lead to disease, most of which are not visible. However, there are symptoms you can see.

Disease Symptoms:

  • Cloudy or swollen eyes.
  • Patches or spots that are cloudy white or gray.
  • Rapid movement of the gills.
  • Opaque, clamped, or frayed fins.
  • Distended or hollow stomach.
  • Wounds or fungus growth.
  • Unusual swimming patterns, darting as if alarmed, hanging at the surface or being shy and hiding.

Reasons for Fish Disease

Once your aquaponics system runs, it will be a closed-loop system, and fish and plants thrive together.

However, there are times you need to do something, and it could be the time a disease is introduced. Diseases may be introduced by introducing new fish, plants, live food, or changes in equipment used in your system.

You will have a delicate balance in your system to make sure your fish are healthy. Fish can be carriers for bacteria, viruses, and fungus as with other animals. While not all are harmful, you’ll find pathogens (microorganisms) that can cause diseases.

Here you can find several factors that can lead to fish disease:

  • Poor water quality
  • Stressed fish
  • Fish species clashing with another
  • Poor or unbalanced diet
  • Fish Stress

How to Prevent Fish Diseases

Although you can get diseases in your fish, there are things to reduce the impact or prevent them from starting.

  • Quarantine new fish for two weeks before introducing them in an established fish tank. 
  • Feed fish on a good, well-balanced diet.
  • Check water quality and make sure it is clean. Too many fish can overload your bio-filter if you have one.
  • Check all your parameters for pH, ammonia, nitrites, and nitrates are in line with the fish you have.
  • Make sure you have sufficient aeration. Add an air-stone and air pump to your sump tank or fish tank.
  • Limit the times you open and close the lid of your tank to inspect fish as this can stress them, particularly if you scoop them out to examine them. 
  • Treat any disease as soon as you identify it.

Common Fish Species for Aquaponics

Tilapia      

Tilapia is the best fish for aquaponics since they quickly adapt to their environment and cope with various water conditions. Tilapia breed quickly in small-medium aquaponic systems and like water temperatures of 82 – 86 °F and pH of 6.5 – 9.

Tilapia are resistant to many pathogens, parasites and can deal with stress as it is a very hardy fish. They also eat a diverse diet and are omnivores who eat plant and animal-based feeds.

Harvest time for tilapia is six to eight months, though this will vary based on water temperature, diet, and size you are harvesting.

Pros of Tilapia

  • Fast growth rate.
  • Quickly adapt to the environment.
  • Great eating.
  • Will reproduce quickly.
  • Omnivorous diet but won’t eat other fish.
  • Can cope with reduced amounts of dissolved oxygen. 

Cons of Tilapia

  • Need warm water above 55 °F.
  • Reproduction speed can be an issue in small systems.

Trout     

Trout are carnivorous cold-water fish, which are closely related to the salmon family. You will find them suitable for indoor and outdoor systems, as they can cope with an extensive range of water temperatures. Trout prefer colder waters of around 56 to 68 °F, so they are suited to cooler climates. Trout are slow growers and are approximately 1 pound in weight in about four years in their natural environment.

Trout needs high-protein diets compared to tilapia and carp. They offer a high tolerance to salinity and survive in freshwater, brackish water, and other marine environments, so a range of conditions in your system should be suitable.

  • Pros of Trout
  • Great fish to eat and packed with protein and omega fatty acids
  • Ideal for cooler climates
  • Have a varied diet and can eat fish, insects, or small invertebrates

Cons of Trout

  • Slow growers.
  • Can’t mix with other fish.
  • Require large tanks for proper growth.
  • Need clean water.
  • Require close monitoring of pH levels.
  • Need lots of dissolved oxygen.  

Largemouth Bass   

The growth rate of bass varies based on tank size, numbers of fish and diet. The average bass could grow between 2 to 8 inches during the first year. From that point, to mature at 10 inches could be another two years.

For breeding bass and eggs to hatch, your bass needs water temperatures of 65°F to 75°F, with 72°F being the optimum.

Eggs hatch in a couple of days after fertilization, and fingerlings are fast growers and can reach 2 inches in 6 months. 

Besides the range of temperatures bass can deal with, they can also cope with low DO and pH levels.

They are carnivorous and need high-protein diets, and you can harvest at one year from fingerlings.

Pros of Largemouth Bass

  • Bass eats almost anything from pellets, insects, and more
  • Great fish to eat

Cons of Largemouth Bass

  • Potassium levels need monitoring.
  • Conditions need monitoring to ensure clean water, oxygen, and pH levels.
  • Bass doesn’t like bright light or poor feeding.

Koi     

Koi are a popular fish for aquaponics yet are not an eating fish and more for decoration. Koi live a long time and breed comfortably in an aquaponic system.

Koi can live off many foods and, in lots of cases, are disease and parasite resistant. Koi like temperatures of 65 – 78 °F and pH level of 6.5 – 8. 

Pros of Koi

  • Disease and parasite resistant
  • Deals with a broad range of temperatures
  • Attractive ornamental fish
  • Long lifespan

Cons of Koi

  • Not suitable for eating.
  • May produce excess waste as they age. Systems may need more cleaning, or numbers need to be reduced.

Goldfish     

Goldfish are another ornamental fish that can be suitable for aquaponics. They are easy to care for and are tough, hardy fish that copes with varied water conditions. Goldfish prefer temperatures of between 78 – 82 °F, with a pH range between 6 – 8.

Since they are small and can carry parasites, goldfish are not suitable for eating.

Pros of Goldfish

  • Beautiful fish
  • Hardy and tolerates pH changes
  • Copes with less-than-optimal water conditions
  • Large producers of beneficial waste for plants

Cons of Goldfish

  • Can’t mix with other fish
  • Not an edible fish

Alternative Fish

There are other fish that are suitable breeders in aquaponics, such as catfish. However, since these are bottom feeders, you need a longer tank than it is in height. For many gardeners, this could rule out this fish.

If you have space and the capacity, you’ll find these are fast-growing and easy to breed fish. You can also mix these with other fish as they stick to the bottom of your tank.

Fish Considerations for Aquaponics

If you want to grow fish to eat and are looking to breed, then you’ll need to meet specific criteria to do this. Here’s a rundown of what you must think about.

Temperature

Some fish species like colder water than others, and as fish are cold-blooded, adjusting to varying water temperatures can be a challenge. Water will have a natural temperature based on your location. Check this before you consider heating or warming your water.

Availability in Your Location

Availability of certain fish can be a factor. Some fish are available in certain areas. You also need to check whether fingerlings are available where you live.

Maintenance

Some fish species can take care of themselves so long as you feed them. They can be hardy while others need more care and can cost more to raise. Tilapia and Koi are hardy fish compared to Trout that need more attention.

Space Requirements

All growers need to know the size of their fish once they mature. Often, you need to thin out your numbers as fish get older to avoid too much ammonia build up. Tank space will also determine the type and number of fish you can have.

With this, you’ll find the filtration capacity of your vegetable section can be affected. Overpopulation, or under population, will affect the growth of your crops.

Conclusion

The above fish can all breed in an aquaponics system with the right conditions. You need to monitor the birth and possibly remove these to another tank.

One of the primary conditions is the chances of overloading your system and introducing the extra ammonia through more significant numbers of fish.

Can You Grow Root Vegetables With Aquaponics?

With aquaponics, the majority of crops associated with this system tend to be of the leafy or flowery variety, with the harvestable part being on the upside of the grow bed, leaving the roots dangling beneath to absorb the life-sustaining nutrients. This tends to be the standard configuration and a very successful one at that.

Many growers are unaware that root vegetables can also be grown with aquaponics in just as healthy an environment, with equally impressive growing results.

Growing Root Vegetables With Aquaponics

Anyone who is immersed in the world of aquaculture can attest to the numerous benefits and the ease of growing herbs and leafy vegetables under this umbrella. For some, it is just a pleasurable pastime, while for others it is a blooming business, with flowers being one of the many beneficiaries of this system.

Perhaps looking to expand the business or wanting to broaden the variety of crops they cultivate, many farmers are looking at the possibility of adding root vegetables to their range of crops. But are all root vegetables compatible with the aquaponics way?

Root vegetables such as potatoes, beets, onions and carrots, for example, are top contenders for aquaponics, but certain changes have to be implemented to make these additions possible, with the growing process not being as straightforward as with leafy plants.

Carrots are probably the easiest vegetable to start with, not only because they can thrive in the aquaponics environment, but because of its hardiness and the colorful varieties available.

Apart from the classical orange variety, there are red, yellow, white and even purple carrots in the marketplace that, although not generally found in local supermarkets, are gaining in popularity. These uncommon varieties, Nantes, Danvers, Imperators and Chantenay, are just four types of carrots being incorporated in the root vegetable section by adventurous aquaponics farmers.

They can be a challenge Like all root vegetables in aquaponics there are initial challenges that need to be overcome, but if done correctly the successful harvests can be an eye-opener, and add different flavors and a splash of color onto the dinner plate.

Traditionally, all root vegetables are immersed in soil for absorbing the right amount of nutrients and water. With aquaponics, this soil has to be replaced by an alternative grow media to achieve a successful harvest.

Growing Carrots Aquaponically

Gravel and hydroton are the medium of choice for underground vegetables in aquaponics, either giving the roots something to grip onto for stability. An alternative to them is coco coir, a grow media that functions exceptionally well if the vegetables are to be potted in a cloth bag or a pot.

In this set-up, the nutrient-rich water from the fish tank will run through unimpeded, and the gentle compression effect from the coco noir encourages the root vegetables to grow to their standard recognizable shapes, rather than shapes that consumers consider to be deformed.

The fish selection also plays a defining role when deciding to go underground, and the most common fish in this type of aquaponics farm are tilapia and trout. These are ideal because many root vegetables can be grown in cooler climates and these fish thrive in cooler waters. Koi and goldfish can also be used if they are not be eaten.

Once the system has been set up and refined, and the correct fish selected for this endeavor, the crops can generally be harvested within two to three months. If there is sufficient space and if configured correctly from the outset, several other types of root vegetables can be grown within the same closed-circuit system.

To make the introduction of root vegetables into an established or brand-new aquaponics farm, there are full kits that can be purchased online or at gardening centers. These greatly simplify the process and reduce the time it takes to set up a fully functioning system.

These kits give detailed instructions on how and when to place the fish in the tanks, the ratio of fish required in relation to the number of root vegetables to be planted, and even when to increase the density of fish. All of this information takes the guesswork out of the installation process, eliminating costly mistakes that could otherwise be made.

Additional instructions on how long to wait after the set-up is completed before planting the root vegetables, the space required between the seedlings so growth is not inhibited, and even when to intersperse more seedlings among them, are invaluable to either an experienced grower or a complete newbie.

Residential Aquaponics Growers

Growing fresh fruits and vegetables has never been more fun and more accessible to residential growers owing to the simplification of the overall process.

Even those home gardeners living in cooler climates and with limited space can take advantage of aquaponics to grow all manner of vegetables indoors or in a shielded environment. The added ability to harvest crops at any seasonal time of the year increases the appeal, and the popularity of aquaponics continues to grow.

Once the mechanics have been mastered, the maintenance routine refined, then the expansion to include root vegetables is an easy step to take. There can be no doubt that in aquaponics healthier onions, potatoes, beets and carrots can be grown organically, and if they can all be accessible right from the bottom of your own garden…even better.

These ventures are sometimes started to save money, to grow healthier, more nutritious vegetables, in an environment that is not at the mercy of nature. What they morph into is a lifelong journey that either stays at the bottom of the garden or grows into a bigger business adventure.

The low maintenance aspect, the convenience, the harmonious nature of aquaponic farming itself, not only make this system sustainable for short-term harvests but ensures that it will continue to expand profitably into other farming categories not previously considered viable.

With the increasing demand worldwide for bolstering the food supply in impoverished countries, growing root vegetables with aquaponics could be a game-changer. Combine that with the fact that this farming method is constantly evolving and discovering better and faster ways to put a healthier meal on a plate, and it looks like aquaponics is finally getting to the root of the food problem.

Do You Need A Greenhouse For Aquaponics?

With aquaponics, the idea goal is to cultivate plants and crops in a controlled environment to achieve the best harvest at a faster rate than with traditional in-soil farming. This can be undertaken in either an indoor or an outdoor setting, where the results will be virtually identical.

The difference between the two will be in the amount of work required in an outdoor setting to combat the weather conditions, to control pests, to fight diseases, and even to protect the fish from harsh direct sunlight. Constant vigilance is required to offset these challenges, and that incurs more expenses and more stress.

A practical solution to balance the scales between starting an indoor or outdoor aquaponics farm is a greenhouse. It eliminates a host of challenges, affording protection against the elements while offering more control over the infrastructure.

Benefits Of A Greenhouse In Aquaponics

Practitioners of aquaponics understand the requirements of having a balanced system where the interdependent nature of the bio-sphere needs to flow seamlessly. Outdoors, there are numerous obstacles looming to create pitfalls that interrupt the cycle if not constantly brought under control.

With large commercial aquaponics farms, larger areas are needed to set up the system that most brick-and-mortar dwellings cannot house. The options are either to install the farm completely outdoors and overcome the challenges as they occur, or opt for constructing a greenhouse that can be customized to suit your personal circumstances.

Immediate advantages of a greenhouse stem from being able to create and nurture a micro-controlled enclosure where out-of-season crops can be cultivated.

Establishing this sheltered environment in a location where there is normally insufficient sunlight or heat can encourage the crops within to be grown to healthier fruition, and the fish reared in a protected underwater world, 

Surrounded by ever-changing seasons or just a naturally colder climate, that warmth can be provided by heat lamps, heat blowers, or some other source of artificial heating. To discharge any excess heat build-up, air vents can be installed to reduce overheating and regulate the temperature.

Conversely, if there is too much heat on the outside that, too, can be mitigated from the glass or plastic material that the greenhouse itself is composed of, or from cooling fans installed inside.

The prime objective of selecting an aquaponics greenhouse is to optimize the health and growth potential of the crops by creating ideal growing conditions and at the same time nurture the lives of the fish. One of the best ways to do that is to protect them from adverse weather fluctuations, pests, and diseases.

A greenhouse affords all of these benefits and is undoubtedly value for money even after the initial investment needed for extra equipment.

The Future Of Aquaponics Greenhouses

Recent studies have highlighted the benefits of utilizing greenhouses for aquaponic farming, not just for commercial growers but for personal ones as well. The flexibility in size availability makes it convenient for all types of environments and growers.

A popular type of greenhouse is euphemistically called the Growing Dome. It is classed as the best for a variety of reasons that include its diverse sustainable growing environment, its ability to foster hybrid conditions, and the inclusion of an above-the-ground year-round pond that is a perfect site to house a fish tank.

Within the Growing Dome greenhouse, there are generally two types of systems, Stand-Alone or Modular. Both have exceptional components that enhance the operational capabilities, but the choice of which is better boils down to the preference and objectives of the individual farmer. With either one, there is a possibility of having two income streams under one roof.

Traditionally in aquaponics, the fish are just a part of the biosphere with their waste being the main bi-product. In a Growing Dome, they can be harvested and sold on to create additional revenue, a major boon for growers both large and small.

This increase in profits will significantly attract more investors into this sector of greenhouse aquaponics farming, especially in colder climates where growing seasons are shorter and more challenging.

Tips For Using An Aquaponics Greenhouse

At the outset, it is important to take under consideration that there are two distinct lifeforms housed under one roof, each requiring different needs to survive and thrive. Crops require more sunlight and heat but can cope with slight fluctuations better compared to their fishy co-inhabitants

To maximize their potential, placing the grow beds in a position where they can take advantage of those two life-giving resources will result in heavier crops and increased production.

Fish, on the other hand, fall into the sun-dodging category, preferring to reside in the shade. If the tanks overheat due to incorrect placement in direct sunlight, the dissolved oxygen will decrease to dangerous levels and can risk the lives of the fish. A key point to remember is that it is a much more arduous task to cool down a fish tank than it is to heat one up.

Fortunately, there are greenhouses specifically manufactured for aquaponics, having an insulated south-facing wall to guard against direct sunlight, yet allowing in enough heat and light for plants and crops to flourish.

Employing the use of one of these greenhouses is a perfect choice to encourage year-round crop growing and harvesting. Its construction allows the warmer interior to be maintained at a stable temperature, while the north wall is ideal for placement of the fish tank, being as it is in a more shaded and cooler zone.

This level of strategic insulation saves on heating expenses and assists in minimizing unwanted temperature fluctuations.

There can be no denying that insulated greenhouses retain more heat than uninsulated ones. They are simply easier to manage in seasonal areas where the temperature can swing from one extreme to the next, from freezing cold to blazing hot.

In harsh winters, an uninsulated greenhouse can be unviable to run, the frozen temperatures on the outside mimicked on the inside, heating costs through the roof, and the effort required to keep the crops and the fish from freezing a constant battle of life and death.

Better Aquaponics Crops In A Greenhouse

Maximum productivity is the ultimate goal when deciding to erect a greenhouse over an aquaponics operation, not only from the choice of fish and crops that need to complement each other but also the layout of the farm itself.

With a brand-new greenhouse infrastructure, a blank canvass is there for your specific requirements and goals. Those can range from the walking distance between crops that need to be tended to regularly, to what the surface of the ground is composed of.

Concrete is a top choice as it can be laid level and smooth and, although expensive, is a good option if wheelbarrows are to be used frequently, as well as being easy to clean. Gravel, pavers, and even dirt can be used, each having its pros and cons, from price, ease of availability, to lack of drainage and uneven surfaces that can impede the movement of produce and equipment.

When the pros and cons of utilizing greenhouses in aquaponics farming are weighed up, the questions to be asked are not whether they should be used, but why are they not being used more often? The reasons for their usage easily fall into the positive categories.

Experienced farmers understand that aquaponics doesn’t need greenhouses to be a successful endeavor. But if greenhouse usage can increase productivity, can further protect the living organisms within, and in some quarters is being hailed as the future of agriculture, then surely, it’s better to be ahead of the curve rather than be left behind it.

Do You Need to Change Water in Aquaponics?

Aquaponics is very similar to Hydroponics in function and system design to a certain degree. Both are soilless systems and use water as the primary way of delivering nutrients. Hydroponics requires frequent water changes, so new gardeners can often ask the following question.

Do you need to change water in Aquaponics? Besides using fish as the source of nutrients in an Aquaponics system, the second most significant difference is you never need to change the water. You will need to top up water lost to evaporation, etc.; however, the system is self-cleaning when in operation.

Why Aquaponics Works?

Aquaponics is the perfect answer to a fish farmer’s need to dispose of nutrient-rich water, and a hydroponic grower’s nutrient-rich water demands.

Aquaponics mimics natural waterways and is a highly efficient way to grow food crops in small areas, yet systems are sustainable.

The primary input in Aquaponic systems is fish food, and as this is eaten, there is fish waste. Over 50% of the fish waste produced by fish comes as ammonia they secrete in urine and smaller quantities through their gills.

The remainder of this waste is excreted, where it goes through a process called mineralization. Here, heterotrophic bacteria consume the fish waste, decaying plant matter, and uneaten food, and all these create ammonia and other compounds.

Once the levels of ammonia rise above certain levels, they become toxic to fish and plants.

In soil, air, and water, you find Nitrifying bacteria, which can convert ammonia first into nitrites, and from there, they create nitrates that plants consume.

Heterotrophic and nitrifying bacteria cling to tank walls, under rafts, growing media, and organic matter in your system.

Such beneficial bacteria are natural and inhabit an aquaponic system when there is any sign of ammonia and nitrite present.

You have three things to keep alive and healthy in an Aquaponic system. You have your fish, plants, and the resulting beneficial bacteria.

All these rely on each other to live and create a circulating system where every party’s needs are fulfilled. Bacteria consume fish waste to keep the water clean for the fish. Meanwhile, the bacteria provide plants with a supply of usable nutrients.

As the plants grow, they use these nutrients, and by doing so, they act as a filter to clean water the fish live in.

Is There Any Reason to Change Water in Aquaponics?

One of the key reasons you may need to intervene and change the water in an Aquaponic system is if you have a severe algae problem.

Algae is a major nuisance and can cause many problems. Two areas that it can affect are the nutrients for your plants and your system’s pH.

An aquaponic system is a self-contained eco-system, and it is for this reason you shouldn’t have ever to change your water.

Not only this, but when you first build a system, they need to cycle to produce the right environment for your plants and fish.

Before you consider changing water, here are some things you can do to help prevent the accumulation of algae.

Shading

Shading is the quickest and easiest way to reduce algae in your system. Green algae need light to grow and reproduce. You can use either shade your tanks or cover them with a dark-colored tarp or plastic.

Many growers do paint sump tanks and any transparent plastic black and then white on top as this can reflect the sun and stop water heating up.

On media beds, if you have algae issues on the surface of your media bed or Bato buckets, you can shade by adding more rock or gravel to stop light from reaching the moist areas.

Filtration

Mechanical filtration can play a significant role in algae removal. Equipment can be expensive, although it’s easy to build. You can use filters, screens, and vortex or centrifugal settlement equipment to remove algae from your system.

A grow bed in your system will act as a large mechanical filter and straining algae from your water.

Alternatives

One alternative some gardeners resort to is using Humic Acid. In a deep tank, you can see the water darken from the addition of this. It is this that helps stop algae growth. You can add humic acid as it is beneficial for your plants to help chelate plant nutrients.

Why You Don’t Need to Change Aquaponic Water

Besides ensuring all your pipes and pumps are clean and working correctly. You will find little you need to do in dealing with your water besides checking pH levels.

You will discover much of this because an aquaponic system creates an eco-system rather than a system, which is fed nutrients as in Hydroponics.

Here you can see the functions of the three zones you will have in your system. It is the function of these to deliver nutrients by breaking down waste—the distribution of this nutrient-rich waste and the sealing layer that aids in preventing evaporation and algae growth.

One thing to note is the depth of your grow bed. It is recommended to have 12 inches, although many growers say you can use a regular hydroponic flood table. While possible, it makes the zones far thinner and restricts the range of vegetables you can grow.

Besides the volume of growing media (gravel) and your grow beds’ weight, it is advisable to aim for twelve inches for the best conditions.

Here is a breakdown of the zones and their function.

Zone 1 – The Surface Zone

The uppermost 2-inches of the surface serves two functions. First, we saw it stops a considerable amount of moisture evaporation because of the dry zone it creates.

Second, pea gravel that is dry in this area helps stop collar rot on your crops. You’ll also find the chances of powdery mildew are reduced, and as we have seen, it can stop algae growth.

Zone 2 – Root Zone

Of all the three zones, it is here where the most activity happens, and all the magic happens. You’ll find this root zone ends up around 6-8 inches in depth. Once the bed has been flooded and drains, you get optimal oxygen delivery to your crops’ roots.

All the activity comes from microbes, worms, and beneficial bacteria that accumulate.

It is the flood cycle that distributes all the waste particles across the growing bed. Works break down any solid matter and release minerals into the worm tea. When you flood again, this worm tea mixes with your water to spread around the roots of your crops.

Zone 3 – Mineralization

In the lowest 2 – 3 inches, you find a slurry of fish waste solids and worm castings. From the first entrance to the system, they will be reduced by around 60% in volume.

Once you carry out your flood and drain cycles, the zone receives a boost of freshness by the actions of the most recent delivery of oxygen-rich water.

Conclusion

You have no reason to change the water in an aquaponics system, yet this doesn’t mean you won’t have maintenance. Even with filters and everything else in place, you can end up with blocked pipes or water pumps.

Your system will do as much as it can to care for itself, yet to make sure you get the best results, it doesn’t hurt to add a helping hand.

Do You REALLY Need A Biofilter For Aquaponics?

Any beginner entering into the aquaponics sphere at one point or another will have this question or topic raised. Being newbies, they simply won’t know what to do at this early stage of their learning curve. But to be honest, there are many experienced growers who are also on the fence, hearing many conflicting voices for and against its usage.

The need for a biofilter is bacteria-driven. Beneficial bacteria are an integral component in the recycling system in aquaponics and help to harmonize the existence and wellbeing of the fish inhabitants and the burgeoning plant life. For a harmonious co-existence, a biofilter is a must have

Why Is A Biofilter Needed In Aquaponics?

Imitating nature is the underlying tenet of aquaponics, creating an environment of co-dependency between fish life and plant life. To flourish symbiotically, each relies on the other for nutrients, food, filtration, the conversion of waste materials into nitrates, and the ability to recirculate cleaned water back into the system.

This self-sustaining environment combines the benefits of aquaculture with the system of hydroponics, but it wouldn’t function quite so harmoniously and seamlessly without bacteria. To understand the need for bacteria it is necessary to know how aquaponics work, and that will determine whether a biofilter will be required or not.

The overriding principle with aquaponics is that there is no reliance on fertilizers to aid in plant growth. That chore is undertaken by nutrients. But where do they come from and how are they replenished?

A closed-circuit system like aquaponics utilizes the water from the fish tank to transport nutrients and water in a closed-circuit cycle. known as the nitrogen flow cycle, to the roots of the plants and back again.

The process is initiated by the waste of the fish and as this waste material begins to decay it starts to be broken down into ammonia. If left unchecked, this ammonia will turn toxic to the underwater dwellers and eventually lead to their demise. Adding to this build-up of ammonia will be the decaying organic matter of leftover food and dead plant segments.

In aquaponics, a conversion process starts to occur due to the interference of beneficial nitrifying bacteria, where the mounting toxic ammonia is converted into nitrite compounds. At this phase, the danger to the fish has been eliminated but the nitrite is still not usable for the nourishment purposes of the plants. What they need are nitrates.

A friendly bacterium called Nitrobacter is the leading protein in the oxidation process that will ultimately convert nitrites into nitrates, so the nutrients can now be absorbed as plant food. Without this beneficial bacterium, the aquaponics farm would fail.

So, if this system functions so seamlessly without any intervention required, why would a biofilter be needed?

The aquaponics closed-cycle system works when there are sufficient beneficial bacteria to complete the conversion cycle. If there is a shortfall due to a lack of surface area for the bacteria to grow, then more bacteria have to be introduced somewhere along the conversion line to make the world go around.

How A Biofilter Works In Aquaponics

Biofilters are essentially a large surface area attached to the aquaponic farm where additional bacteria can set up a colony and grow, increasing the efficiency of the nitrification process if it is underperforming.

Bacterial conversion, from ammonia to nitrites to nitrates, occurs in all aquaponics systems. The need for a biofilter can become necessary if there is an increase in the fish stock in the tank. This can be the result of a spike with breeding, and if so more fish generally equates to more poop, and proportionally more waste means more ammonia.

If this accumulation continues unchecked, the aquaponics farm can enter into the forbidden zone very quickly. Therefore, it is imperative to recognize when the biosphere is in jeopardy and act accordingly to expand the playing field. Fortunately, a biofilter will correct this imbalance automatically if connected to the circuit.

The setting-up process of interconnecting the two and expanding the surface area is not that complicated. It consists of another tank with one or more air pumps that are used to push water from the new side to the old, so they now operate on the same circuit.

Sand or gravel is most commonly used as the growing medium as it allows the colonization of the bacteria to progress easier. Nitrifying bacteria start to proliferate on the expanded surface area and, because bacteria require oxygen to grow and thrive, the biofilter should be set for additional aeration for maximum growth.

Plants will now be able to perform their duties after receiving the nutrients, by cleaning the water which is then returned back to the fish tank to start the cycle all over again. This expansion increases the efficiency of the nitrification process considerably.

All of this process is important to the chemical stability of an aquaponic biosphere, the wellbeing of your fish, and the successful growing of your crops. And the good thing is that nothing goes to waste, recycled as it is again and again.

A Biofilter in All Aquaponics Systems?

An aquaponics farm is in essence its own filtration system. And an efficient one at that. But with two living organisms to co-exist together a balance has to be reached or one will thrive and the other will decline. There are several factors that need to be considered.

The pH balance is front and center among them. A reading of 7.0 to 7.5 is considered neutral and is ideal for both organisms. If that level drops below 6.0 the nitrification process will slowly grind to a halt and become toxic to the fish and the plants will not receive enough nutrients.

Regular monitoring will detect the pH imbalance which can then be corrected before it gets into this danger zone.

This recalibration occurs naturally in a system that has a growing medium of gravel, clay or lava stones as long as the surface area is large enough to encourage bacteria growth. In this case, a biofilter will not be necessary, the grow beds themselves being the ultimate biofilter.

Problems occur, however, when this natural filtration system is overwhelmed by fish waste. This imbalance arises if more fish are added at a later date, or more fish are birthed in the tank, or even if too much fish food is being entered into the habitat, not eaten, sinks to the bottom and starts to decay. Either one of these will spike the production of ammonia.

Types of Biofilters

When installing a biofilter the location has to be situated after the mechanical filter as it is not designed to handle large fish waste deposits which can become trapped in the pipes. If this happens, the waste will continue to accumulate, creating an aerobic zone that will encourage excessive bacteria growth away from the expanded surface area which will not be utilized, and that will reduce the efficiency of the biofilter.

The mechanical filter acts as a screening filter to control this build-up of solids so the level of ammonia will not become too much for the biofilter to cope with.

There are various models of biofilters but these three are the most frequently used:

A Moving Bed Filter, also known as a Moving Bed Biological Reactor (MBBR), is a biofiltration model that is constantly in motion and at its core revolves around K1 media and constant aeration.

K1 media are made of small plastic discs and are ideal at trapping particles suspended in the water, and their large surface area encourages the growth of bacteria. With their virtual neutral buoyancy ability, they are subjected to a steady stream of air pressure that aerates the water and pushes them around.

This type of biofilter is essentially a constant flow system that uses an air pump to keep well-oxygenated water churning over, essentially creating a biological reactor. This system keeps the K1 media floating and in motion, assisting in the collection of good bacteria, and is especially effective in a raft aquaponics system.

Due to the collision of the media, each disk performs a continual self-cleaning process and this helps by keeping the nitrifying bacteria rejuvenated for optimum ammonia and nitrite nitrification.

A Static Filter biofilter has the advantage of the ease of use and ease of setup. It is essentially a flat tray in a separate container next to the plants, filled with a media mat to provide a sufficiently large enough zone to grow the necessary bacteria needed for the biofilter to work to its fullest potential.

The deeper the media incorporated, the more beneficial bacteria will be nurtured. Here, the principal theory is the water flows through the tray at one end into the media, the conversion from ammonia to nitrates occurs, and the cleaned water flows out through the opposite side back into the closed system.

With a Drip Filter, the water drips into the system from the top, passes through the bio medium at a slow rate, performing the vital conversion process from ammonia to nitrates, and flowing out the bottom on its way back to the fish, completing the cycle.

The Need For The Biofilter

A biofilter doesn’t have to be a part of the aquaponics system from the initial set-up. It can be integrated at a later stage as and when needed. The good news is that its inclusion isn’t a costly addition, and some would say it’s better to have it in place on standby if needed urgently. It is always better to have a quick fallback solution on hand if a nasty build-up of ammonia surges unexpectedly.

The fact that a biofilter requires very little maintenance is a reason all in itself to have one. There is no downside to having one even in this self-sufficient aquaponics biosphere. It can be implemented at any time to regulate ammonia, supplying enough oxygen for additional bacteria growth when required.

Sometimes adjustments in the aquaponics system can create an imbalance between ammonia build-up and lack of nitrates. This can occur due to plants being replaced, reduced and the opposite reactions can occur if the fish population is increased.

What has to be considered, and is often overlooked by beginners and some experienced aquaponics farmers, is the age of the fish being added into this bio-sphere. To maintain the equilibrium a specific stocking method has to be adopted.

This includes having a staggered age range of the fish throughout the same tank and employing a harvesting regime every three months. A recommended approach is to harvest the more mature fish who are now weighing about 500g and restocking them with new fingerlings or juvenile fish weighing about 50g each.

This staggered approach is to avoid swapping out of all the fish at the same time and to alleviate the sudden impact on the system. If a full fish exchange took place at the same time, out with the old and in with the young, then that would result in too much of a drastic adjustment requirement in regards to the filtration process.

Another reason for implementing this rotation is because larger fish tend to eat more than their juvenile co-inhabitants. And when larger fish if eat more they are going to excrete more waste. If this re-stocking process is not utilized, ammonia can reach unfavorable levels, rising completely unnoticed until something starts to die off.

Monitoring and reacting to this fluctuation can take years of experience as well as constantly keeping a close eye on the ph level. With a biofilter connected, these fluctuations are automatically adjusted as the water and the waste are washed through it, maintaining the delicate balance of this bio-diverse system.

The bottom line, the final word, on if a biofilter is necessary for a self-sustaining system like aquaponics, is yes.

Without one, time-consuming re-calibration tasks would need to be incorporated into a more frequent maintenance routine.

With one, your aquaponics farm will be a problem-free dream to run, and your plants, your fish, and your precious time will be the happy beneficiaries.

Can You Grow Onions in Aquaponics?

Onions are a staple diet for millions of people around the world and are grown in a myriad of environments to add flavor and texture to many a dish.

The idea of growing onions in an aquaponic system is not only possible but maybe a preferred method of farming to achieve a growing system that would reap a more organic harvest than traditional outdoor planting.

You can grow onions in aquaponic systems. Flood and drain or Nutrient film technique (NFT) systems tend to work best as the roots of onions need plenty of moisture.

Let’s have a look at how this system would work.

Onions and Aquaponics

Growing onions in a field is a labor-intensive farming method and requires pesticides, herbicides, and chemicals to eliminate pests and diseases. And they need a lot of watering.

There are several new revolutionary ways to grow crops over the last few years that have enabled city dwellers to grow onions, fruits, vegetables, and even grapes in an urban environment. These methods have breached centuries of traditional farming and have, in many cases, made it possible to grow staple food products in areas previously unviable and unachievable.

All these systems rely on regular maintenance techniques and nutritional systems to assist in the growing process, and any failure in the chain can lead to a lost or diminished harvest.

In aquaponics, the best of each of these techniques are utilized in a controlled environment to nurture the growth of onions, while the downsides of many of them are discarded.

No pesticides or chemicals are used, the time-consuming maintenance process is eliminated and even the harvesting process is simplified.

Aquaponics is about harnessing the power of nature itself to create a self-sustaining eco-system. It works by converting the natural waste of fish into nutrient-rich water that is transported through the system to be absorbed by the roots of the onions, and then the cleaned water is returned to the fish tank.

Once the system is installed there is very little ongoing work or maintenance required. This closed-loop aquaculture works harmoniously with the onions and the fish flourish mightily within this self-contained eco-system.

How to Grow Onions in Aquaponics

Creating a continuous cycle is the tenet of aquaponics.

This particular method requires an aquarium, a pump to move the water back and forth from the aquarium to the roots of the onions, a grow bed where your onions will be located, and a selection of fish for the tank itself.

The grow bed can either be placed on top of the aquarium or off to the side. The grow bed, or flood table as it is also called can simply be a plastic tray or a large container as long as the support structure is strong enough.

Once you have decided on the location and how big you want your aquaponic farm to be, select the size of the aquarium. By using an aquarium instead of a solid container, gives you the benefits of having and enjoying your pet fish while growing your new onion crops at the same time.

At this stage prepare the fish tank as normal by dechlorinating the water and then allowing sufficient time for the bacteria to build up over the following weeks.

This is the starting point to set up your very own fully integrated ecosystem. It works by having the natural waste from your fish being broken down into nitrates, and then a pump carrying these nitrates to feed the roots of the onions. Nitrogen is then released by the plants, cleaning the water which is then safe to be pumped back to the fish, and then the cycle is repeated.

This process is on a continuous loop and the only time water has to be added is if there is a marked level of evaporation or if it is transpired by the plants.

Three Ways to Grow Onions in Aquaponics

There are essentially three types of aquaponics that are used depending on growing experience, the space available, and the scale desired.

The Deep-Water Culture Set Up lets the onion roots drop into the water and take nutrients directly from the water. This method is suitable for a larger scale operation.

The Nutrient Film Set Up is where the roots are left to dangle in a PVC pipe drilled with holes. The water is drawn into the pipe to run over the roots, delivering much-needed nutrients before being fed back into the tank. This method is suitable where space is a consideration and is flexible enough to allow crops to be grown vertically, horizontally, up walls, or even hung from ceilings.

The Media Bed Set Up is the last method and is the most convenient for home growers with little experience, and who opt for a smaller-scale operation. Here the plants are seated in a bed of expanded clay pebbles or gravel, and a pump draws the water from the tank to flow over the roots.

Normally onions require space between the next clove to grow as about a dozen shoots sprout above ground. In aquaponics the bulbs can be set a mere inch apart, allowing more to be grown in a smaller area.

Caring for your Onions in Aquaponics

Growing onions with aquaponics will give you the option to decide how big you want to grow, whether your intention is to feed a small household or a community of onion lovers.

It all depends on the size of the area you have available, from a ledge in your bedroom to a large greenhouse in a nearby field, and, of course, what your goals are. Even the strain of harvesting can be mitigated with the grow bed set to a height totally at your discretion for comfort.

Less water is used due to the closed-loop ecosystem, with hardly any at all being wasted. With this consistent water availability, the bulbs have a tendency to start sprouting quickly as long as the temperature range of between 55°F to 75°F is maintained.

Aside from the importance of having the correct temperatures, having the ph level right is just as crucial, but it can be a little tricky. The onions, the fish and even the bacteria being formed in the water are three distinctly separate living organisms, and all have different ph requirements.

This ph level can be affected by the fish waste, and that can adversely impact the ability of the plants to absorb nutrients, which will reflect negatively on the lives of the fish. So, as you can see the balance of the eco-system as a whole has to be finely tuned regularly.

The optimal range of ph for aquaponics is around 7.0. To ensure a continued harmonious system, it is advisable to monitor this neutral ph balance on a daily basis to avert any wild fluctuations and to keep within this ph safe zone.

And the type of fish selected for this project can make the task of maintaining your onion farm easier also.

One of the ideal types of freshwater fish to use is, believe it or not, is the humble goldfish. They tend to excrete large amounts of waste so your onions won’t be short of nutrients in the conversion process.

But koi can be used, as well as tilapias, and really any hardy fish will do that require minimum maintenance. After all, the beauty of aquaponics is not just the onions you will be growing tenderly, but the aquarium full of colorful, interesting fish that you will be enjoying at the same time.

Harvesting Aquaponic Onions

Aquaponics is a symbiotic relationship between plants and fish and goes hand in hand with sustainability. This collaboration uses less water which is cost-effective and good for the environment and produces 100% organic produce.

Really there is no limit to where your onion crops can be grown with aquaponics and an added bonus is that the growing times are accelerated. This results in a quicker crop of onions being harvested more frequently and, due to this system being so self-contained and self-reliant, the whole interconnected process becomes a game-changer in the field of growing onions.

All in all, aquaponics combines all the new innovative growing methods together with the flexibility to be scaled to fit over a small aquarium filled with an array of multi-colored fish, or scaled upwards for a much larger industrialized farming operation.

Can there be a better way to grow your onions?

Can You Grow Broccoli in Aquaponics?

When you first run either a hydroponics system or an aquaponics system, it’s hard to know which crops are best to grow.

The smaller systems lean toward shallow rooting vegetables, which are mainly herbs or leafy green sorts of vegetables for salads. However, larger systems can cater to larger crops, and with space, they are perfect for tomatoes, cucumbers, peppers, or other vining vegetables that need room to spread.

The question comes down to root vegetables and the possibility of growing them. You can find out the answer, and then other information about growing this healthy vegetable.

Can you grow Broccoli in Aquaponics? You can grow broccoli in your flood and drain media bed or Dutch bucket type system. You find broccoli isn’t so much a large crop; it is heavy. This weight makes it unsuitable for floating rafts, nutrient film, or other similar systems. It is worth growing in larger, supportive beds. However, there are a few other growing demands of this healthy crop you need to know.

Broccoli and Nutrient Requirements

To grow broccoli efficiently, they require lots of nutrients, and thus you may need to adjust the fish population to accommodate this crop.

You will also find it far better to attempt growing broccoli in aquaponic systems, which are well established. Fish levels may be better if they are around 1lb of fish per eight gallons of water rather than 1lb of fish for every 10 gallons.

With a perfectly functioning system, the nitrates’ levels should be 50ppm or as close to this as possible. Besides this, the levels of ammonia need to be low, even with increased fish density.

Besides this, the other two key nutrients are magnesium and phosphorus, or you may see crop growth slow.

Growing Instructions

When you come to transplant seedlings into your media bed, you ought to do this once they have 4-5 true leaves showing. Your crops at this stage will be around 5.5 to 8 inches tall.

The germination time to reach this stage can be around 4 to 6 days. Besides this, you need to consider the spacing for transplanting as broccoli comes with a large root system.

Seedlings should be planted from 17 to 20 inches apart from each other. Closer than this, and you can see your crops producing smaller central heads.

Growing Conditions for Aquaponic Broccoli

Broccoli is a winter vegetable and won’t take too kindly to growing conditions that are too warm. While it is a beneficial crop to grow, it is on the side of moderately difficult.

You can find seeds that will be bolt resistant to help, though trying to maintain the ideal temperatures will help considerably. Broccoli thrives the best in daytime temperatures of 57 – 62 F (14-17 °C).

Winter varieties will require temperatures around 50 – 59 F (10-15 °C) for the head formation. Temperatures above these are possible, so long as there is a higher humidity level available. Should temperatures be too high (over 65°F), this will cause premature bolting.

Also, broccoli likes full sun for around 6 hours per day. It can cope with a little partial shade, although this could make broccoli mature at a slower rate.

Broccoli can deal with swings in pH levels, although for the health of the rest of your system, aim to keep it at a more neutral level of pH 6 to 7. A digital pH pen is ideal for checking the levels frequently.

Harvesting Broccoli

It would be best if you started harvesting broccoli for the best quality when head’s buds are firm and taut. Harvest immediately when the buds separate and show their small yellow flowers. To preserve taste, it is important to harvest the broccoli in the morning.

You should cut the heads off your plants and take at least 6 inches of stems diagonally below the head.

Most varieties of broccoli have side shoots that develop after the chief heads are harvested. You can harvest from one plant for several weeks, sometimes, from winter to the beginning of summer as long as summer temperatures are not too hot.

Pests and Disease in Broccoli

Many crops in your aquaponics and hydroponics systems often face less intrusion of pests and disease. Although broccoli is one that, like cabbage, can be prone to the effects of cabbage worms and other pests.

Here are some pests or disease you will need to be wary of when growing broccoli in aquaponics.

  • Aphids: Curled leaves may show the sap from your broccoli is sucked up by insects. A way to combat this is to apply soapy water on all sides of your leaves whenever you see aphids.
  • Cabbage Loopers: If you see small holes in your leaves between the veins, they may result from green caterpillars. Check the underside of the leaves. You can pick these off by hand if the problem is small or fight the problem with Bacillus thuringiensis, a natural bacterial pesticide.
  • Cabbage Worms: Such worms, Whiteflies, or cabbage root maggots can be treated the same way as you treat any cabbage loopers.
  • Clubroot: Rapid wilting of plants can be attributed to this fungus. Your entire plant, including all its roots and tendrils, needs to be carefully unearthed and removed from your media bed. If roots appear gnarled and misshapen, then the root of the club is causing the problem. You will need to remove infected plants swiftly, so the fungus will not continue to spread throughout your system.
  • Downy Mildew: When purchasing broccoli seeds, make sure you purchase varieties resistant to downy mildew. Otherwise, you will spot the yellow patches that are caused by moist conditions. Aim to keep crops dry, and they have plenty of air circulation.
  • Nitrogen Deficiency: Broccoli is a nutrient-loving vegetable. If your fish tank isn’t large enough to cope with numerous broccoli plants, it could lead to a slight yellowing of the bottom leaves rising upward on your plants.

If you have the capacity, you can plant marigolds or calendula flowers close to your broccoli as these help fend off the above pests that take a liking to your crops.

Aquaponic Broccoli Varieties

While there are many varieties of broccoli available, not all are suited to aquaponic cultivation. Here, we have the top three to consider should you decide on broccoli for your soilless system.

Chinese Broccoli

Despite being a broccoli variety, it differs greatly from other cultivars because it grows without florets. Also known as Kai-Lan or Chinese kale, this variety has large, thick leaves with a bitter taste compared to Calabrese and sprouting broccoli.

Chinese broccoli grows quickly, at around 35 days, and thrives well in warmer environments, making it ideal for growing in the summer.

Sprouting Broccoli

In contrast to Calabrese, this kind of broccoli shows more stems and smaller single florets than a central head. Sprouting broccoli is more bitter than other species and can be purple or white.

White-sprouting broccoli is milder and slightly sweeter in flavor than its purplish equivalent.

Calabrese Broccoli

You will be more familiar with the Calabrese Broccoli since it is the most commonly sold variety in stores and markets. The heirloom plant was named after Calabria or “the toe” from the Italian peninsula.

Gardeners highly recommend it because Calabrese broccoli offers an extended harvest period, as it forms side shoots that remain in place after removal of the main head.

Conclusion

Although broccoli can be more challenging to grow than many other crops, so long as you have deep grow beds to offer support and maintain the desired temperatures, there is no reason you can’t dedicate a grow bed to this crop.

While it is usually a large grow bed, you can use a Dutch bucket system to make sure they have ample support. You then have the flexibility of your spacing and won’t waste valuable space in your main bed.

While a challenging crop, broccoli is worth the effort because of its rising costs in the stores and its many health benefits.