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.

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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.

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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?

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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.

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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.

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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.


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.

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What Size Gravel is Best for Aquaponics?

In the same way that hydroponics is a soilless means of growing, so is aquaponics. One of the key differences being the way the grow beds are constructed. While hydroponics systems tend to grow in pots in various systems, an aquaponic system most often uses flood and drain grow beds, which are full of growing media. Gravel being the most common.

What size gravel is best for aquaponics? There are many sizes available, and in theory, any size gravel can be used. Most hydroponic gardeners prefer pea gravel, which is between 1/8 of an inch up to 3/8 of an inch in size. Although, the smaller 1/8 sized pea gravel being the gravel size of choice. 

Considerations of Aquaponic Growing Media

When you first build any aquaponics system, there needs to be a few considerations when choosing the ideal growing media. Here you can find the things you need to think about, and you can see why pea gravel is the ideal media to use.

Inert: Any aquaponic grow media needs to be pH neutral. Similarly, as a hydroponic system, the pH level in an aquaponic system needs to be controlled.

Fish and plants have their preferred range of pH range, and ideally, you need to aim for a range of pH 7. Many media can change the pH level, although pea gravel isn’t one of them.

All you need to do is thoroughly cycle your system before adding fish or plants to clean away any dust.

Grow Bed Depth: Any grow bed in aquaponics should be a minimum of 12-inches deep for most crops.

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Weight: Any grow media in use in a hydroponic system should be too heavy to handle. It should be light to medium weight, so you can easily dig your holes when you plant your seedlings. On the flip side, if they are too light, they can float in the grow bed and won’t offer support.

Easy to Work With: Grow media can comprise any size or shape, although sharp edges are best avoided. If you use sharp-edged stones, these can be hard on the hands and damage any grow beds that are not constructed from solid materials.

Non-Decomposing: No aquaponic grow media should break down because it can work its way through your system and clog your water pump and reduce dissolved oxygen in the water for your fish.

Pea Gravel for Aquaponics

Pea gravel fits all the criteria and then some. The smaller pea gravel has a large surface area that bacteria can thrive on. With this, the nitrogen cycle is complete and, in turn, delivers robust plant growth.

From the fish waste, the broken-down compounds create ammonia, which passes around your system. Once it flows through your smaller sized pea gravel, it is converted into nitrites by two bacteria strains (Nitrosomonas bacteria).

From here, these nitrites are consumed by the second strain of bacteria (Nitrobacter bacteria) and converted to nitrates. Your crops then use the nitrates as fertilizer.

As there is more surface area on the gravel, a larger number of nitrates are being produced than if larger gravel was being used.

Pea Gravel with Limestone

Generally, your pea gravel won’t contain anything to change your aquaponic system’s pH level radically. However, if there are any traces of limestone, the results could be different.

Before filling your grow beds, you can carry out a test to check whether your bags of small pea gravel.

Take a handful of gravel, place it in a container, and then cover it with some white vinegar. You can see the vinegar fizzles if there are traces of limestone.

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You need to avoid limestone as this will keep your pH above 8, which can harm your plants and your fish.

You can place some gravel in distilled water and check the pH after a couple of days, although it is better not to purchase any gravel you think may be suspect.

One thing to note is that the name pea gravel isn’t a type of gravel, it is because of its size. One dealer can sell something different to another.

Grow Bed Depth and Pea Gravel

One thing any gardener needs to understand when using pea gravel is the depth of the grow bed. The recommended depth is 12 inches, and for a good reason. When building a system, you may be tempted to go for a shallower bed.

Even while pea gravel is the cheapest media you can purchase, the amount you need could be considerable. However, there are reasons why you should opt for a grow bed of this depth, if possible.

Here you can see why avoiding the shallower bed sizes can be beneficial, and it is advisable to scale your system to support the larger bed and the increase in the size of the fish tank you will require.

You will face limitations if you decide to go for a shallow grow bed filled with pea gravel.

Eco-System & Dead Zones

In deep aquaponics grow beds, you naturally create a layered eco-system. One significant benefit of this is that you will prevent any ‘dead zones’ dotted around your grow beds.

Besides this, as you have a thriving environment packed full of beneficial bacteria, worms, and lots of space for roots to grow. You don’t have to clean out your grow bed.

These bacteria and worm communities, along with your plants, do all the cleaning for you. Anything less than 12 inches, and you won’t be able to reap these benefits of a stable eco-system.

Plant Limitations

If you are growing nothing but crops similar to lettuce, you may get away with a grow bed shallower than 12-inches.

However, if you grow indeterminate tomatoes, cucumbers, and corn among the many other crops that can benefit from aquaponics, these shallow beds can’t support them. You won’t receive the same base nutrients and beneficial bacteria for these longer living crops.

One thing not to forget is your aquaponic system can be highly configurable, and you can mix grow beds and use raft systems for short rooting crops and larger grow beds or Dutch becket systems for deep-rooted crops.

Three Zones of Pea Gravel Grow Bed

Zone 1 – Surface Zone

The top 2-inches serve two purposes. It allows for light penetration and acts as the dry zone to limit evaporation. The second reason for this dry zone in your pea gravel is to prevent collar rot and stop any algae forming as the nutrient-rich solution faces light exposure. Also, the infection from powdery mildew is minimized.

Zone 2 – Root Zone

It is in the second or middle layer where the plant activity occurs. Making up this layer is around 6 to 8 inches in depth. As you drain after flooding your grow bed, water drains away completely and presents highly efficient oxygen delivery to the roots, microbes in the soil, worms, and beneficial bacteria.

When you are in the flood cycle, incoming water will distribute all the fish waste particles containing nutrients through the entire grow zone. Worms are highly active in this middle zone, where they break down solid matter to release minerals and add to the underlying worm tea. On each successive flood and drain, this beneficial tea is spread around all your crops.

Zone 3 – Solids & Mineralization

Once you reach the bottom 2-inches, you find all the fish waste solids and worm castings are gathered together. By the time it reaches here, it will have been reduced by around 60%.

In each of your flood and drain cycles, this zone is kept fresh from the effective delivery of oxygen-rich water.


Once you see the benefits of using 1/8-inch pea gravel, you can understand why it is among the most popular media.

It is highly affordable, and any gardener is advised to lean toward the deeper grow beds when possible. Besides this, there is nothing you need to do with pea gravel, and it is one of the easiest materials you can work with.

There is nothing but benefits you can get from using this smaller sized pea gravel than if you used a larger gravel, or an alternative growing media.

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How to Fix and Prevent Nutrient Burn

When growers first start running a hydroponic system, one of the first problems they encounter is what we call ‘Nutrient Burn.’

The problem sounds much worse than it actually is, and manifests from growers who give their plants too many nutrients or fertilizer. The way it manifests comes in a couple of differing ways. The first being leaves which appear scorched on the tips, and the second area, which isn’t as obvious, is that of root burn.

This can be more severe on your plants as there will be the drying rims of the leaves. Roots, which are turning brown, will accompany this and plant growth will be slowed quite considerably.

Here, we will look at all you need to know about the exact causes of nutrient burn, and what you can do to fix the problem and prevent it occurring again.

Why Do Plants Get Nutrient Burn?

Because it is down to the grower to provide the correct nutrients to plants in a hydroponic system, the problem ultimately comes from the grower.

A logical thought when first beginning a system can be, the more nutrients, the better my plants will grow.

Unfortunately, this is far from the reality. When growers overfeed their plants, it will lead to them being ‘burned’ in either of the two ways previously mentioned. To fully understand why this happens, it is good to know what these burns are.

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These spots are not physical burns as if the plants were on fire. These are more like burns you get on your skin from a toxic compound. Nitrogen is one of the major compounds that makes up hydroponic nutrients.

Even though overfeeding plants is the main cause of this problem, it can stem from other areas.

  • Mixing nutrients too strong
  • Over-watering – plants need dry periods where they can absorb oxygen
  • Boosters for blooms – used on some plants, and when used too often or too strong it causes toxicity
  • Plant growth stimulants – if these are used to frequent, it can cause dwarfism in plants and they will try to absorb too many nutrients

Once you begin overloading your solution with these compounds, your mixture quickly turns into a toxic substance. Hence, this is where leaves begin burning. Any grower who overfeeds their plants can spot the following.

These are early indicators their plants are over-fed and will end up with nutrient burn.

  • Tips of leaves burn and turn yellow
  • Leaf tips turn bright green
  • Leaves turn darker green
  • Stalks and branches may turn dark red. Purple of magenta
  • Leaf tips bend at 90 degrees

How Do I Fix Nutrient Burn?

We saw Nitrogen is one of the main compounds, which leads to these issues; it isn’t though the only one. Once plants are reaching the end of the vegetative stages of growth, plants will be looking for more calcium and magnesium.

If these are overfed, the same symptoms will transpire in your plants. Fixing the problem may appear daunting to new growers, yet it is easier than they may think.

Following some simple steps can mean the difference between saving crops and losing a host of plants.

  1. Get rid of burned or damaged leaves
  2. For extra security, trace backward on the calyx clusters to their supporting branch and remove the entire floret.
  3. Discard any dead leaf matter as this will rot and cause contamination
  4. Flush your growing pots and the growing medium with clean pH balanced water.
  5. Check your tank’s pH and EC levels. Adjust this using fresh water only. You can drain your system to be sure you have no nutrient excess in your reservoir. Run for 24-hours with just fresh water and test EC. If high, drain and repeat the process, and check. Continue until your EC levels are acceptable.
  6. Depending on the extent of the nutrient burn, you can ease back on the nutrients in your mixture and supplement this with an organic liquid tea for around seven days.

Preventing Nutrient Burn in My System

This kind of problem usually happens by mistake, and for this reason, it can be something, which is easy to prevent happening again.

Taking on some, good habits can help prevent this. Here are some pointers, which will help prevent nutrient burn:

  • Use the right nutrients for the correct growth stage
  • It is advisable to use 3/4 strength, which is given on the packaging – manufacturers are not always right.
  • Use digital pH/ EC meters to check your nutrient strength at regular intervals or when you are topping up your reservoir.
  • Always flush your growing medium and pots with your system to stop salt buildup.
  • Use the best measuring device for the nutrients. A kitchen-measuring spoon, which is exact to the dose, makes things easier.
  • Never look down on the line of measuring jugs. Always look at eye level when reading measuring lines.
  • Be sure to use distilled water, as this won’t aggravate the problem by adding more nutrients.

As you go through all of these steps to eradicate the problem, you need to try to figure out what caused it in the first place. Fixing the issue is only any good if you know what not to do next time.

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Additional Steps for Prevention

One of the main things new growers do is to not fully understand their plants requirements. Each type of plant differs. Understanding this as well as what is already in your solution are the very first steps in prevention.

Different crops do have different requirements. A good rule to follow is that leafy crops like herbs, spinach or lettuces need higher levels of nitrogen. If you are growing fruits like cucumbers, peppers, eggplants and tomatoes, then these will be seeking lower amounts of Nitrogen.

If you attempt to grow any root vegetables, these require higher amounts of potassium.

Regardless of which plant type you are growing, there are different nutrient requirements for different development stages. Understanding what plants need in their flowering or bloom phase as compared to their growth or vegetative stage can make a massive difference.

One final thing, which has an effect, is where your plants receive their light source. If you are using grow lights indoors for your crops, these will again be looking for different nutrients and levels than crops grown outdoors.

Generally speaking, crops require more nitrogen if they are receiving full amounts of daylight, or they are being exposed to high doses of artificial lighting. This has more of an effect when crops are outdoors.

If your plants are following regular growing seasons, crops which produce fruits will be looking for more potassium in the late fall or winter when levels of light are reduced. Although the levels of Nitrogen and Potassium can be increased to double the requirement in wintertime, this will not be the case under grow lights where conditions will be consistent.

Problems with Concentrated Nutrients

It can be a good cost saving to use concentrated nutrients. However, the use of these needs plenty of due care and attention. These concentrated formulas are often where new growers become mixed up and don’t fully understand the bottles instructions. 

Not making a conversion in your quantity can leave plants open to burn straight away. As well as this, if these nutrients go anywhere near your plants in their undiluted form, they can quickly kill your crops. No grower should be mixing concentrated formulas in their grow room.


Adding too many nutrients won’t deliver bigger plants and larger fruits. This is a common mistake, yet when you look at all the above information, you can see it can be resolved quick, and while saving your plants.

The good thing is that any grower can learn from their mistakes, so for this to happen a second or a third time? There is no excuse.

There is only so much you can give you plants before you smother them. It is like being a regular parent with your child. Give them what they require and they will blossom, give them too much, and the results are never what you expect.

Related Questions:

Is nutrient lockout the same as nutrient burn? The two are similar, and some of the symptoms may appear to be the same. However, nutrient lockout is where your plants are unable to absorb the nutrients you are giving them.

What causes nutrient lockout? Over time, your pots and growing medium will have an excess of salts that build up in certain areas. If these are allowed to carry on accumulating, they can bind some of the nutrients and prevent them from being available to your plants.

How do I fix nutrient lockout? The good thing is you can solve nutrient lockout by following the same steps as for nutrient burn. Although these two things are different, they cross paths and begin to show similar symptoms. The main thing is to use plain water to dissolve and flush this salt accumulation from your system. If these remain, the problem will occur as soon as you begin adding more nutrients.

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Can You Grow Grapes Aeroponically?

The simple answer is yes. But it’s not just as easy as popping a piece of the vine on a stick or a trellis and you’re good to go.

With proper planning and finding the right space to suit your needs, however, growing grapes aeroponically can reap rich rewards, enabling you to harvest healthier grapes faster, eco-friendlier, and pesticide-free.

Aeroponics vs Tradition

Growing grapes outside has been around for centuries, being a very successful farming method passed down from one generation to the next. The view of a large field filled with rows of vines is a spectacular sight, an iconic picture on many an Italian or Spanish hillside as well as in numerous other countries in the world.

So, to diverge from this renowned method to one that is relatively new, well, there has to be more noticeable benefits. 

Above all, what aeroponics allows is for your average person to start growing grapes without having to own large swathes of land, without having decades of experience or a large bank account,  and being able to take advantage of unused areas in an urban setting.

Scientific progress and invention, as well as advancement in machinery and equipment, has cultivated this new innovative system of growing grapes, eliminating many obstacles in the standard grape growing process.

Cultivating the grapevines in an indoor, controlled environment has numerous advantages. The first is space. 

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Although seeing a field filled with vines as far as the eye can see is a sight to behold, perhaps it is not the most economical method to grow grapes for the masses.

A huge amount of land is required to do this, and that land, that soil can determine the quality of the grapes. Another determining factor is the weather that fluctuates with the seasons throughout the year-long growing season and can adversely affect the crops.

Growing grapes inside with aeroponics eliminates these two barriers to successful grape growing immediately. 

Also since the roots are free-hanging they do not need to be planted deeply in the soil, the vines do not need to be planted to face the sun and six feet apart, as well a host of requirements to be undertaken painstakingly just to keep them alive and pest free.

As long as certain requirements are met for optimal plant health, for growth, and the indoor environment is optimized for grape development, the aeroponically growing grapes could be the way to go in the future on whatever scale or size imaginable, big or small.

After this article, you’ll have more of an idea of what to do, what not to do, and even how to do it.

First, let’s look at what exactly aeroponic growing is and why it’s the new way to grow.

Aeroponics? What’s that exactly? 

Awareness of indoor farming has been increasing in popularity recently as the potential of growing crops in a controlled environment is becoming more apparent and appealing. 

With this flexible method of indoor vertical farming, crops can be grown year-round regardless of any extreme changing weather conditions in the area, and also it allows a higher number of grapes to be harvested with less spoiling due to infestation, disease, or a variety of mitigating circumstances from excess rain, to adverse weather conditions and even to too much sun. 

For growing grapes, aeroponics can prove to be very advantageous.

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Traditionally growing grapes in soil requires a distance of about 6 feet of space between each vine and each plant is going to need a lot of sunshine to ripen the fruit. Once the new shoots start to develop, called canes, they are then pollinated by insects and the wind. 

An irrigation system can be set up to provide sufficient water and pesticides and chemicals are used to ward off insects and protect against diseases.

It can take up to a year of pruning, spraying, and watering before the plant bears any fruit.

Aeroponics does it faster, cleaner, and eco-friendlier.

Easy Aeroponic Set Up

Vertically growing grapes in an indoor space turns all of this system on its head, so to speak.

In fact, there are two methods of indoor growing. 

The first and more common method is hydroponic growing.

This involves submerging the roots of the vine in a container with filtered water that has a pH level of between 6 -6.5 and using a filtration system to regulate the amount of water applied to the roots.

Growing grapes aeroponically compared to hydroponically is a little bit more of a complex system, however.

Aeroponic growing involves suspending the plant roots in the air and watering them periodically rather than submerging them in a container.

This is achieved by suspending the vines in a foam plank, for example, with the roots left to dangle in thin air. Water is applied by using a misting system that is set on a timer to spray filtered water every few minutes that is mixed with a nutrient-rich solution to provide sustenance.

This method is extremely effective but requires a fairly complicated set-up that is easy to master in a short space of time. With a bit of patience, all can be set up and operational in no time at all.

After a period of trial and error, if you are new to this process, you will become aware of what needs to be done periodically to help your vines to grow healthily and steadily in these conditions, which will make every re-growing season in the future that much easier.

Benefits of Aeroponics

Rather than waiting up to a year for your harvest to ripen, the grapes can be cultivated in a shorter period of time, being harvestable up to 25% quicker, a major benefit if you’re short of space and even shorter on patience.

That’s one of the benefits of this system. 

It’s as if devoid of the constraints of soil or a containerized system, the roots of the vines take advantage of the extra oxygen flowing constantly and being so readily available, that the results are a faster growth spurt.

Efficiency is also a key benefit here also, with less water actually being used and lost to evaporation, 95% less in fact, and the water can even be recycled along with the nutrients to make this process cost-effective, saving on wastage and being good for the environment.

Pesticides are a thing of the past here as well, as they are simply not needed. When the equipment needs to be cleaned and maintained, everything can be sterilized simply, eliminating the need for harsh chemicals.

Growing vertically also reduces the amount of space required to grow larger quantities in a smaller space compared to outdoor lateral growing, and the upside of the closed-loop irrigation system is that there is no runoff of harsh chemicals to foul the surrounding ecosystem, making this method eco-friendlier.

If a small DIY model is all you’re after without automation, then it can be set up inexpensively from as little as about $100. 

A professional aeroponics turn-key system, on the other hand, could cost well into the four figures if built at scale, with nutrient monitoring equipment, a backup power supply, pumps, timers, thermostats, tubing, and a pressurized water tank capable of delivering the finest possible puff of moisture, to name just a few equipment requirements.

Constant Grape Attention.

The system utilized for aeroponics is a closed system that has to be monitored on a regular basis, not only to check that the spray timing hasn’t failed, but also to maintain the misters to ensure that there is no clogging of the spray holes. 

The nutrient concentration also has to be recalibrated constantly so the precise parameters required for the crops are the same and do not fluctuate excessively. Too much variance in the cocktail of the pH balance can be detrimental to crop growth, and can even lead to loss of an entire crop if not monitored regularly.

Another worst-case scenario is if there is a power cut for a certain amount of time, the roots can stop being misted and become starved of nutrients. However, with proper vigilance and the right monitoring back-up systems, this worst-case scenario can easily be avoided, and a hassle-free growing cycle can be achieved time and time again.

Aeroponic Needs

Everything needs food and light to thrive, stay healthy and productive and grapes are no different. In their case, they need nutrients that aeroponically will be provided by adding magnesium, phosphorus, calcium, and other nutrients to the water periodically. And they need light and energy to survive and thrive.

Because aeroponic crops are grown indoors in a sheltered environment special lighting has to be installed to provide this life-giving nutrition.

These energy-intensive lights have to be installed to harness sufficient light to give the plants the energy needed to grow and these are normally run using electricity. Solar energy could be a good alternative option, however, if possible.

So environmentally wise this is not an optimal situation. And since the water pumps rely on electricity, well, you can see that the profit margin can take a hit as the pumps have to be running constantly.

Growing Indoor Temperature Changes

Something to consider when looking at growing grapes aeroponically is the space that is going to be used as that will determine the equipment required. Humidity is also a factor that has to be considered as is temperature, and air quality.

If you were setting up in a greenhouse, for example, circulation fans may have to be installed to control the temperature. The fans would be required because the use of lamps installed to create light often emits a fair amount of heat and this hot air has to be vented. 

If the temperature is too high problems can occur because the vines will require more water than usual which will affect the timing of the misting system and the nutrient content in the water.

In other words, the vines will get thirstier and need more water to survive. So, if the temperature fluctuates too much, the misting systems would have to fluctuate accordingly, which would make a complex job even more complicated.

Conversely, too low a temperature will slow down your plant’s growth and absorption of nutrients, creating another problem.

The solution with the fans is to have them connected to a thermostat for automation, exchanging the heated air inside with cooler air from outside to maintain a controlled atmosphere.

If a different indoor space is being used apart from a greenhouse for aeroponic growing, a similar system can be set up but just on a smaller scale.

The Humidity Factor

Mold problems can occur if the humidity is too high and the vines can even overheat if the ambient atmosphere is already saturated with moisture. While rare with aeroponics, too dry an atmosphere will cause excessive water absorption of the vines. 

To maintain balance, a humidistat can be used alongside a thermostat or a single combined thermostat/humidistat as a better option to tackle this potential problem.

Automation is highly recommended to keep a close eye on the temperature and to maintain a humidity level of between 60% to 70%, perhaps with a warning signal to alert you to anything requiring immediate attention.

Wrapping Up

The advantages of aeroponically growing grapes in this fashion are numerous and far outweigh the teething glitches initially encountered with setting up this system.

However, with the numerous benefits of a faster growth time, more control of the environment, an organic, pesticide-free product, well, it’s definitely worth the small initial hassles.

So, whether it’s just to have a better, tastier grape for your own consumption or to make your own wine, this revolutionary system could be for you. For the casual grower, having your own crop of grapes hanging from the vine and grown by your own hands can’t be bad either. 

What’s not to like?

Have a grape day!

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Is PVC Safe for Aquaponics and Hydroponics?

More and more individuals are turning toward growing their foods. Since the limited amount of space some people have, they seek alternative and inventive ways to grow vegetables. With this, came the advent of hydroponics and also a fork of this we know as aquaponics.

Many of these systems will be based around piping and tubing to transfer water. It is possible to purchase made for purpose pipes and tubes, yet the DIY nature of many system builders is they turn toward PVC pipes and tubes. You find these components are readily available and highly affordable. However, it does lead to one question.

Is PVC safe for Aquaponics and Hydroponics? There are various standards of PVC, and some are not suitable for either hydroponics or aquaponics. However, there are standards which can deem some PVC as food safe. Before you build your system, it is good to understand the types of PV and the concerns some individuals have.

What Are the Types of PVC?

Here is an overview of the various strains of PVC.

Plain PVC

You will find this in two forms. You have one which is an unplasticized polymer (uPVC) and a flexible plastic.

In the unplasticized form (uPVC), the PVC is rigid and stiff; you will find these two traits make this PVC highly-durable when you compare this to your regular PVC which is much softer, pliable and flexible and also not as durable.

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CPVC is a chlorinated type of PVC which offers some unique properties. It provides high glass transition temperature, chemical inertness and high heat distortion temperatures. You often find this in use for mechanical, smoke-related scenarios and dielectric. From the name, you can see it contains a higher degree of chlorine than regular PVC.


This variant of PVC is incredibly tough and possesses vast amounts of impact strength.


Out of all, PVC-O is the strongest and offers very high tensile strength. It is often used in applications where this strength will be a benefit.

Are PVC Pipes Toxic?

The main types of PVC you may use for your systems will be PVC or uPVC, and it is here where the concerns lie.

Instead of thinking, PVC is flexible, while uPVC is rigid. You will find more to it because there are reasons this occurs. When there are no plasticizers added, you end up with a rigid product, and thus it takes on the term of Foods Safe PVC.

Food Safe PVC doesn’t have any Bisphenol A (BPA) or Phthalates, and the lack of these make it safe for use in gardening, regardless of the type. If you are unsure, what you need to be aware of is any mark or stamp that shows the PVC is to NSF-51 rating, and thus, safe for food production.

NSF or National Sanitation Foundation is the organization that does all the testing and sets the standards for public health and environmental safety.

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Once your PVC has this NSF-51 rating, you know it meets all the set standards for ‘Plastic Material and Components used in Food Equipment.’

Why is Regular PVC Not Safe for Hydroponics?

While you can see standards that are in place and why uPVC is safe, you ought to understand why regular PVC isn’t food safe and shouldn’t be used in your Hydroponics or Aquaponics gardens.

PVC (Poly Vinyl Chloride) is a thermoplastic polymer they make from various chemicals, which can comprise of Phthalates, Lead and Cadmium. You will find all of these are toxic to humans.

Besides the toxicity of these compounds, when you burn PVC, it gives off a dangerous chemical named Dioxin, and which is a class 1 carcinogenic.

What makes things worse is you cannot recycle PVC pipe. When it faces exposure to sunlight for extended periods, it can pass lead ash through the pipe.

Because PVC has been around for a large number of years, there are landfills and gardens, which are full of PVC pipes breaking down under the force of the sun to create a health hazard to humans.

Even if you are using uPVC in your system and it has exposure to the sun in your hydroponic or aquaponic garden, it may be wise to cover these pipes in some reflective paint or cover. If nothing else, it can help to keep your hydroponic reservoir cooler, which is a good thing.

Gluing PVC Pipes in Hydroponic Systems

With the NSF-51 rating, and the NSF-61 rating determining your PVC pipes are food and water safe. Even if regular PVC is safe if it is out of sight, there is one area which you can find isn’t typically mentioned.

When gardeners build their systems, they may need to glue certain connections. While it is preferable to leave them as a pressure fit, it isn’t always possible to do so.

The problem of over gluing comes into play. Much of the thought goes into the safety and toxicity of PVC, yet the chemical cement is highly toxic. You can obtain a good idea from the smell it gives off, and the feelings of dizziness or you find it hard to breathe if you are in an enclosed area.

PVC cement shouldn’t end up on the skin, and you should never inhale the fumes if possible. When used correctly, there isn’t too much of an issue; it dries quickly and takes you seconds to apply it.

The issue comes from applying too much glue, and when this happens, it can pass into the water. If this were to occur in a hydroponics system, you could clog your pump, yet in aquaponics, it could cause harm to your fish.

What are the Other Types of Plastics?

If you counted the types of plastics in production, you could reach numbers in the thousands. However, here is a handful you may be more familiar with. The FDA sets higher standards for any plastic that will come into contact with anything to do with food or beverages.

  • PET or PETE: Polyethylene terephthalate falls as number 1 in the recycling triangle diagram. It is a clear, strong plastic you will see in use with plastic bottles of water, juice, soda, and peanut butter and spreads. You will find it comes in varying degrees of thickness.
  • HDPE: High-density polyethylene sits in second place in the triangle as is often used for your milk and juice containers as well as some laundry products. You find this plastic thicker than PET and can be clear or colored.
  • PVC: Polyvinyl chloride as we see is best left to what it was designed for, although it can be sued in food production. It is, however, essential to be sure it hasn’t been treated for use in industry.
  • LDPE: Low-density polyethylene plastic is most typically seen in use as bags for frozen foods, bread bags and squeezy bottles.
  • PP: Polypropylene is the one we may see quite often in yogurt or margarine containers and medicine bottles.
  • PS: Polystyrene, is a foam, yet still a plastic. You’ll see PS in plastic plates, cups, cutlery, egg cartons, and meat trays depending on the grade it is made to.
  • Other: Number 7 on the triangle code can be a mix of the above materials or resins not listed. Being food safe, you can find it in use for 5-gallon water bottles, citrus juice bottles, and others.


When building a system, or adding to it, if you choose your PVC safely and make sure it comes with an NSF-51 rating, then you shouldn’t have issues. Keep it out of the sun and try not to use glue, and you will be well on your way to healthy veggies without any worry.

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Are Jiffy Pellets Good for Hydroponics?

There is no secret that hydroponic growers are always out to find the best products and techniques to get the most vigorous growth and best yields possible. Because of this mentality, many skip seeds and use seedlings to save time.

When transplanting, there are many options available, peat pellets, Rockwool, coco coir and others. One new kid on the block is the Jiffy Pellets, and for new gardeners, they can be the most straightforward way to get your seeds going.

However, the question remains, because there is a debate on these small plugs.

Are Jiffy Pellets good for hydroponics? Many gardeners say they should use no peat moss in hydroponics when starting seedlings. Once these break down, they end up in your reservoir and can clog your pump. Jiffy Pellets are in mesh, so are these starters any different?

What are Jiffy Pellets?

You will find Jiffy pellets sold as small dry disks. When you add water to the dry peat moss, they will expand. Because of this, and to stop them breaking apart. It contains all the peat or substrate in a fine mesh. This acts as a pot around the material.

You insert your seed in the top and press it into the potting mix. As the seed germinates and roots grow, they arrive at the mesh. Depending on the plant, some roots find the mesh a barrier and remain inside.

Other roots may push through the holes, although as there are no external growing media, they will be root pruned.

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Once seedlings are ready, they can be transplanted. All you need to do is drop the Jiffy into a hole and start feeding it.

While very convenient, because they don’t need other pots and potting mixes, and they take up very little space. They are more expensive than a traditional pot and growing media.

Besides this, there are concerns about your plant health, the environment, and if they are actually suitable for hydroponics.

Why I Shouldn’t Use Jiffy Pellets

Hydroponics is a soilless gardening system, and from the seeds to the plants, it is the gardener’s job to deliver the right amount of nutrient solution for their growing needs. Add in lighting, temperature and moisture, and you can find this control just can’t be achieved in soil.

To pass water around your system, you need a water pump, and here is where the debate starts. They make Jiffy Pellets from peat, and as soon as you add water to the flat disks, they expand. Over time the peat eventually breaks down, it can work loose from the mesh and find its way into your system to be flushed to your reservoir, where it clogs your pump.

You will find alternatives like Rockwool or coco coir, or a similar growth media is best for seedlings in hydroponics.

You find that because of the potential pump issues, peat pellets are perfect for seedlings, which you will eventually transplant to soil.

They prove Rockwool and coco coir ideal as growing mediums as they retain water and allow oxygen in the right amounts. Aside from this, they are less likely to break down and clog your pump.

Peat Pots and Environmental Concerns

Jiffy Pellets has claims of biodegradability, and have labels as being composed of natural materials. You will expect the pellets to lose their tidy packaging mesh when it merges with the surrounding soil.

However, there is one thing to note, and that is the lack of given time frame the mesh material is given before it decomposes.

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Many gardeners take up the role of growers as they become more environmentally conscious and wish to change their lifestyle to a greener and more efficient manner.

With Jiffy pellets, there are concerns of the biodegradability of the mesh, because there are reports from regular soil gardeners, they don’t decompose as people expect. Even after two years in soil, the Jiffy Pellet mesh is mostly intact, aside from tears where roots work their way out.

Are Jiffy Pellets Good to Use in Hydroponics?

You can find some reports that gardeners do use Jiffy Pellets in hydroponics, yet they place these inside mesh pots to make sure they can sit in their system.

There are reasons Jiffy Pellets shouldn’t be used in your hydroponic system.

Mesh & Roots

If you were to use these pellets in your hydroponic system, you wouldn’t be able to do so as they are. Many plants become rootbound inside the mesh, and you will find stunted growth of your crops. The way around this is to remove the mesh and then remove the peat from around your plant’s roots.

To do this for multiple plants is time consuming and you can cause stress or damage to your plant roots as you rinse them in water to clear away the peat. You then have to dispose of the mesh separately.


The consensus between growers is not to use peat or any similar growing media inside a hydroponic system. As your solution flows, you can find the peat accumulates inside your system as it tangles with roots to cause a blockage, or worse, it finds its way back to your reservoir and blocks your water pump.

Should this happen, all your crops can be at risk of not receiving water and nutrients.


Jiffy pellets comprise peat moss as their primary material. While this offers lots in the way of nutrients, many individuals are unaware of the ecological concerns of using peat moss for anything.

Peat moss doesn’t have an infinite supply. Around the world, there are only so many areas where peat moss can be located, and the mining of this occurs much faster than nature can produce it. A peat bog may only grow by 0.02 inches per year.

Mining of the peat is another factor. Peat holds carbon that will be released into the atmosphere when mined, and it continues to do so long after mining ceases.

The miners also need to drain the water from the bogs, and by doing so, this can have a severe impact on the surrounding water table. Such is the effect, peat is becoming less of a primary growing media in any form of gardening, and alternatives are being sought.

Best Jiffy Pellet Alternative

The drawbacks of using Jiffy pellets should be sufficient for any gardener to see they shouldn’t be used. Because of this, indoor gardeners seek alternatives, and one of the best is coco coir pellets. While there is still a manufacturing process, the fibers used to make these pellets were once a waste product in the coconut harvesting industry.

Coco coir has many benefits going for its use. It has fantastic water retention properties, and there is sufficient space in the fibers for rapid root growth and oxygenation. As an aside, you can find insects are not keen on settling in this media.

Coco coir is also reusable depending on how you use it in your system; all it takes is cleaning and sterilization before it’s ready to use again. One downside at present being it is still more expensive than peat to use.


Jiffy Pellets are convenient to use, yet they are more geared to seed germination than cloning. Many hydroponic growers prefer to use cloning as their preferred method of introducing plants into their system.

With this, there are few reasons you need to opt for using Jiffy Plugs in your system as they don’t offer any advantage over other forms of media for cloning.

Last, you can also do your bit by not using them and preserving an extra minor part of the natural environment.

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Can You Use Rockwool Insulation for Hydroponics?

Some of the growing media used in hydroponics can become expensive. Because of this, gardeners are always on the lookout for alternatives. One of the most popular growing media you can choose is Rockwool, which is a man-made product where they take rock and sand and heat it to extreme temperatures before they sin it into fibers.

The end product is very similar to the slabs of Rockwool insulation often used in the construction of homes. With this, many gardeners wonder.

Can you use Rockwool insulation for hydroponics? On face value, there is little to distinguish between the two materials. They look and feel the same; however, the differences come with the treatments applied to the insulation. We can use it for hydroponics with some care, but it may not be as effective.

Why Consider Rockwool Insulation?

You may wonder why growers even consider using the insulation rather than the Rockwool, which is made for hydroponics.

A couple of reasons being price and availability. You can find Rockwool insulation at most hardware stores, while hydroponic Rockwool you may need to order online.

Rockwool Insulation Vs. Hydroponic Rockwool

Before thinking you can use the Rockwool with no effect, it is better to understand what the differences are. It would not be very smart to find you have changed your growing media to see your plants suffer without checking what impact a new growing media could have.

Added Chemicals in Rockwool Insulation

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Some of the fundamental differences between the two forms of Rockwool are the chemical additives there are. You find these are added to the insulation to make it fireproof and safe to use in your home.

While making them safe for home use, the accumulation of these chemicals over your plant’s life can have a detrimental effect.

Here are two of the compounds added that can affect the growth of your crops.


Using asbestos in Rockwool insulation has been on a decline since they found it led to cancer. They banned the asbestos material from most products during the 80s. However, you can find traces of it in old homes around the country.

When using insulation Rockwool, you can see plants have reduced levels of nutrients in leaves and can suffer from stunted growth as a result.

For humans, there can be irritation of the skin and throat if you breathe in the microscopic fibers. Hence, if you do use this, you need protection if the material is dry.


In manufacture, the addition of Formaldehyde is to act as a binder. However, by the end of the production cycle, they remove most of this chemical, though there are still some traces remaining.

The issue here is if you are using blocks of insulation Rockwool to grow numerous plants, then the levels of Formaldehyde in your system can increase. The effects of this chemical on plant growth are around a 27% decrease in the wet weight of a plant. Also, the water content of your crops can decrease by around 5% per plant.

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In use, there is the side affects you may face, from eye, nose and throat irritation through excessive exposure to your insulation Rockwool.

Plant Growth Using Insulation Rockwool

One of the visual differences you may notice if you hold the two compounds next to each other is how much more compressed insulation Rockwool appears to be. Because of this, the roots of your seedlings may struggle to spread in their early days.

As a result, you may see a limited amount of growth from your crops in comparison. Some tests also show that several seeds may not make it past the germination stage when using this material.

If you wish to proceed with this material, you need to prepare it first before you carry on using it.

Treatment of Insulation Rockwool Before Use

If you want to use the material, or you don’t have a choice at that moment, here are the preparation steps you need to follow to negate the adverse side effects of using this material.

While you need to go through these steps of preparation, you need to know that the structure will change, and the insulation Rockwool won’t return the same form as it was before treatment.

1# Washing the insulation

The best way to remove chemicals from the insulation is soak the material in a solution of water and dishwasher detergent, for around 24-hours.

2# Sterilization

You often use this step when reusing your Rockwool blocks again. With the use of Hydrogen Peroxide, you can sterilize your insulation and remove any disease or traces of infectious impurities.

3# Soaking

Rockwool has excellent water retention properties; however, the insulation variety doesn’t offer as much as the Hydroponic Rockwool.

With both types, you need to first soak your material in water until no air bubbles come from the water surface. Once there are no bubbles, you are guaranteed moisture reaching your seeds, seedlings or plants if using 4-inch blocks.

4# Adjusting pH Levels

Rockwool has a higher pH (7.8) than other growing media, so you have to bring this back in line, so it favors your crops. If you don’t do this, then you can affect the pH of your nutrient solution.

If you are using the insulation for germination or seedlings, they won’t be in your system, and you may not yet be using any nutrient solution to feed them. You can soak your cubes in pH adjusted solution to bring it in line during these stages.

Cutting Rockwool Insulation

One area rarely talked about when using insulation Rockwool is not the preparation above, yet the preparation to sit your plants in the blocks.

Hydroponic Rockwool comes in cubes of various sizes and can be from starter plugs to larger cubes to use in flood and drain systems. The larger cubes have an out paper covering to help keep the material in shape.

Aside from this, the starter plugs and the cubes mainly come with pre-cut holes. When deciding to use Rockwool insulation, you will need to do this yourself.

Here’s a quick guide on how to prepare your insulation by cutting the Rockwool. You will need to make sure you soak your insulation to prevent exposure to dust and fibers.

  1. Remove your insulation from the water and place it on several sheets of newspaper.
  2. Gently press the top of your cubes or slab to remove some water.
  3. If you have a slab, try to mark out your blocks and cut these to shape with a sharp knife or scissors.
  4. Mark out and cut two diagonal lines from corner to corner of your blocks.
  5. Take your sharp knife and cut through your blocks about 1/2-inch in depth.
  6. Because you won’t have holes to drop the starter cube into, the way you use your insulation is peeling back the four corners in the center of your block.
  7. Insert your starter cube and push the corners back.


One thing to note is that insulation Rockwool doesn’t possess anywhere near the same water retention properties of Hydroponic Rockwool. When you compare, you may even say it repels water.

While there are a few differences in the manufacture, composure and the way it works in a hydroponic system, it is possible to use insulation as a replacement for hydroponic Rockwool.

The primary question is if you want to go through all the effort to use a cheaper material, yet can be harmful to yourself, your plants and the environment?

Rockwool may be one of the best growing mediums for hydroponics, yet you can find many alternatives that are just as good, and coco coir being a quick example.

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Can Cereals be Grown Hydroponically?

With many countries looking to solve food shortages, hydroponics has been seen as another way to maximize crop output without using more arable land, which is diminishing each year.

The main staple crops in many countries are wheat, oats, barley, rice and others. This leads to the question, “Can cereals be grown hydroponically?”

The answer to this isn’t as clear-cut as yes or no. With a carefully built hydroponic system, almost any crop can be grown, yet there some plants, which by their very nature are not designed to grow in hydroponic systems, and others which take more effort than the gain form their yields.

Here we will look to see if this question has an answer one way or the other.

What Can You Grow in Hydroponic Systems?

Many growers have systems inside their homes and make use of growing lights. However, there are also gardeners that are lucky enough to have enough space and can utilize a greenhouse to be the home to their system.

This means they can make use of the sun during the day, and then use grow light as an artificial supplement to the natural light.

Greenhouses can offer a gardener more room, yet these can quickly be outgrown with the wrong crops. When you use a greenhouse, you can see larger yields and it is these, which causes the issues.

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Some crops, which are ideal for hydroponic growing, are:

Tomatoes: These thrive if grown in a hydroponic system. Depending on the variety, they will need support for their vines. This is the same if you were growing cucumbers, peas and beans.

Strawberries: These are another great crop to grow in hydroponic systems; however, they can be hard for new growers. There are many varieties, some vine while others are bush growers.

Herbs: Many herbs can be grown and take up very little space.

Leafy greens: Lettuce, kale and many other crops are ideal for growing in a system. These shallow rooting plants thrive in these growing conditions, and it is these, which began the hydroponic boom.

Many other vegetables are suitable for hydroponic growing. These can grow throughout the year, so the chances of fresh food all the time is a distinct possibility. Many smaller plants will grow faster than larger ones and take up less resources and effort.

What Not to Grow in Hydroponic Systems

Even though there are many plants, which are shallow rooted and perfect for hydroponics, there are as many, which are not suitable. These can be for differing reasons.

The first category of plants are those that don’t grow very well in a hydroponic system. Potatoes, yams, sweet potatoes, onions, garlic, carrots and turnips will all thrive better in soil grown condition than in a hydroponic system.

Even if you are a gardener who has a greenhouse, there are still crops that can outgrow these spaces. Squash, melons and many other crops that grow across the ground are not suitable because of the space they take up. These can be grown in hydroponics, yet you will need plenty of space, and then the crops grown per square foot ratio will plummet.

There are a few vining plants that are not suitable for home growers. Depending on the variety, tomatoes and cucumbers can fall into these groups. With trellising and the amount of space needed, they can overwhelm a gardeners growing space.

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Adding to this, these large vining plants can drain systems of nutrients, and finally, there will be a continual need for grow lights to be adjusted as the plants grow along their vines. The extra work required can make these plants more effort than the gains that can be achieved.

Plants Which Don’t Make Economic Sense

There are many crops, which don’t make economic sense to farmers and their hydroponic system. Cereals fall into this category although there is a way where growing some cereals can make sense. This we will see later.

If you take wheat as the example, this is one of the most widely consumed cereals around the world. While not being genetically suited to hydroponic growth, there is the factor of the amount of electricity required to grow it.

To grow enough wheat to make a loaf of bread can cost upward of $20 if it was in a warehouse setting. Add to this the amount of space that is needed to grow enough wheat germ to make this loaf. There is no real feasibility for doing so.

Hydroponics is about saving space while growing more. In contradiction, wheat would take more space to grow a sufficient amount of crop, which is any use.

To break this down into a scale that is easier to relate to for a small garden, if you were to have nine square feet of growing area, this would produce around 4 cups of wheat for every harvest. This equates to making a loaf of bread every five months or so.

While this may write off the chances of growing cereals using hydroponic methods, there are ways where hydroponics can be used for cereal production.

Cereals and Hydroponic Water Purification

The American Journal of Agricultural and Biological Science carried out a study back in 2008. While this wasn’t solely about growing wheat, barley or oats hydroponically, it was about using aquaculture wastewater.

This is dependent on the size of garden, and will be geared more too commercial ventures. Taking the wastewater from system flushing can be used for irrigation of these cereal crops. The study showed the seeds were germinated in a hydroponic system where they then received the wastewater from the aquaculture system.

The resulting crops grew faster and didn’t show any sign of mineral deficiency. They did lack any significant amounts of protein, and even for fish food, they would need a supplement to correct this.

Although this isn’t essential growing cereals in a hydroponic system, it does show they are not adverse to absorbing hydroponic nutrients, so the possibility is there is other factors are ideal.

Hydroponic Cereal Sprouts and Microgreens

Sprouts and microgreens are taking the world by storm. These are highly nutritious and tasty. One of the ones which is touted as being a wonder food is “Wheatgrass.”

This is the first few inches of wheat as it begins its growth. Growing wheat or other cereals to maturity may not be cost effective, yet when you grow them to this stage only, they make a lot of economic sense.

You may see wheatgrass around in juice bars or health food stores. It comes with lots of possible health benefits and can be harvested in around 7-10 days.

Any cereal which is grown in this way will be packed full of nutrients and antioxidants. These can be used to help fight inflammation, diabetes and many other ailments.

Most of these can be grown with a weakened nutrient solution in coco coir while stacked on shelves with a grow light above them. They may take minimal watering, yet they still need all the same elements as the rest of a hydroponic garden such as temperature, ventilation and light.

A grower who ventures down this road may be surprised how much demand there is for this kind of small crop. Microgreens are in high demand from restaurants to the health conscious, even if the garden isn’t a commercial venture, it can lead that way, or just deliver many healthy things to spice up the dinner table.


Asking the question of whether or not cereals can be grown hydroponically does leave plenty open to debate. The reasons for not growing wheat is more down to the sense of doing so rather than it can’t be grown to a mature plant hydroponically.

Once you look at sprouts and microgreens, nearly all cereals can be sprouted or grown to a certain age that makes the minimal effort of doing this well worth it for every grower. This way, you can grow more crops in a smaller space and faster than plants reaching maturity.

A defining answer for growing cereals would be yes, but just not in the ways, you expect plants to grow. As you can see above, at the current time, there are many other crops that can be grown in hydroponic systems, yet the ways systems are set up, they are not a viable crop to do so.

Be it for growing constraints or the economic side rules them out, it doesn’t mean they can’t be grown using these methods.

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Why Do Hydroponics Need Flushing?

New growers will often become confused when flushing is spoken about. It isn’t so much how to flush that becomes confusing, it is the “Why do hydroponics need Flushing?” which can catch them out. One of the first reasons is purely and simple as a means of maintaining system cleanliness.

The second is a little more in depth because it occurs at a different time, and for a very specific reason.

Here we will look at both kinds of system flushing, why there is a difference between flushing a system after a harvest as opposed to before a harvest, and how you can flush systems quickly and easily.

In a quick summary, here is what routine flushing of systems can help with:

  • Removes excess of salts and harsh compounds
  • Ensures a balance of nutrients
  • Allows you the opportunity to clean a system
  • Restoring crop growth in dying plants
  • Leading to better growth and flavor

Flushing Plants for Maximum Yields and Flavor

This can be the area that confuses new growers, and can cause them to make mistakes which affects the final growth of their plants and crops.

Flushing before a harvest doesn’t need to be complicated, and it doesn’t matter what brand of nutrient mixes you use, it can still offer you many benefits.

Why flush before a harvest?

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What growers may not understand is that flushing systems before harvest is an easy method of increasing the final crop quality, to top this, it is free to do.

The reason this helps is, the process plants go through in the vegetative phase where they absorb the nutrients can actually cause them to have a buildup of salts or other compounds, which are not beneficial.

If these are left in the system during harvest phases, it can lead to a compromise in the outcome of the crops. This final flushing has some potential benefits like reducing harshness of the product and removing traces of chemical taste from crops.

This leads to a final improvement in overall plant quality as the plants are not wasting any energy to absorb nutrients as they would usually.

When and Why to flush before harvests?

It does take some consideration when to begin flushing before a harvest as it can have repercussions. If you do this too early, you won’t be just removing these excesses, you will start to deprive your crops of nutrients and leave yourself with nutrient deficiencies.

Growing medium in use can also make a difference. DWC growers can have the shortest flushing time as whatever they do will have an immediate effect. If using coco coir, then this can have the longest flushing time because the medium retains a high level of nutrients.

The ultimate goal is to rid your plants from the excess salts, however, when you use plain water, you are relying on this to cleanse your plant, growing medium and root system of these salts. You are actually starting to starve plants right before a harvest. While this may sound counterproductive, it does force the plants to use any excess nutrients they have in their system.

It is here where plants take on a more natural flavor and smell. There are solutions you can purchase which contain chelates. These can remove the harmful residues from all the areas of plants and systems, as they contain a broad type of chelates for this purpose. End results of crops can be bountiful and these solutions are shown to be effective, yet some can cause shock to plants.

Flushing to Correct Nutrient Lockout and System Cleans

While we have this kind of flushing second, for many growers, it can be the more common kind of flushing they will ever do. It is this flushing, which can be very useful when plants have nutrient deficiencies, or they are showing signs of toxicity.

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Growers may be doing everything right, and still they find their plants are exhibiting these symptoms. It can be frustrating, and as they try to correct these problems, they make matters worse and risk losing all their crops.

In most cases, it is the mineral buildup as seen above which causes these issues. There are different methods you can use depending on system type. As we saw, a DWC system or an aeroponics system doesn’t have any growing medium. Flushing this can be as easy as draining your tank and making a complete swap of solutions.

The reason being, there is no growing medium to hold these excess nutrients. If you are using coco coir, Rockwool or any other soilless growing media, then this can be more intensive. To do this, you will need a solution to be pulled through your medium to flush out the excess salts.

As we saw above, you can purchase dedicated flushing mixes, although, you can do this with a diluted solution. A diluted solution may be advisable, as your crops will already be accustomed to this, albeit in a stronger ratio.

Fertilizers can be weakened to 1/8th strength, adding to this, you will need between five and ten times the regular amount you feed to your plants.

Many growers may skip this step, carry out a full system flush, and start again. While this is the definitive way of knowing what your nutrient levels are, and what your pH level is, this can be a solution to correct your nutrient lockout or deficiencies without putting a halt to your system and cleaning while it is full of plants.

Do I need to flush with Organic Fertilizers?

Organic fertilizers work in different ways when they are in a hydroponic system. Many growers do make their own rather than option to purchase the regular three-pack-solution of nutrients.

If you use organic fertilizers, it will be a case of monitoring systems to check the TDS, the PPM and the pH level. In many cases you can find out there is no need to flush during transition as the type of nutrients being administered isn’t changing to such an extent.

Generally speaking, organic will have microorganisms which are breaking down before being fed to plants. This does however take place in soils or growing mediums. Some growers will still flush their system with fresh water in the final week to be sure there is no ill effect.

One thing to notice is there will be no salt build up when using organic nutrients as there isn’t the same composition of salts that normally causes issues.

Flushing Systems for Cleansing Purposes

If you are flushing to keep your system clean, you will find the steps are the same regardless of nutrients used. The only difference being the kind of system you have. Here are the basic steps of flushing to keep your system clean:

Draining your reservoir

If using a water pump, drain down suing this and a run-off hose. Water levels should reach the top of your pump where you then scoop out the remaining couple of inches. Some reservoirs come with drain valves, if you have a drain area, you can drain directly by using this.

Cleaning the Reservoir

Remove any sediment or algae and then top up with water and use the hydrogen peroxide cleaning method for sterilization. This will be easier to clean than using bleach as this needs triple flushing to remove all traces.

Fill the Tank

When cleaned, rinsed and wiped dry, you can fill your system and let it run before checking the pH levels. You can then add your new batch of nutrients and re-check your readings. When these are in line, you can begin adding your plants to your system.


As you can see, there are a couple of reasons why and how you can flush your systems. Not every method works for every grower because no two crops are the same. Many growers experiment to find the optimal flushing methods.

This is more the case during transition as there is more of a final effect on the resulting crops (crop dependent); however, this kind of flushing can leave crops tasting more natural.

This alone makes flushing during the final week of growth worthwhile. Having a bumper crop that doesn’t contain any taste of nutrients will be hard to beat in anyone’s book. Not to mention, it can make cleaning your system easier once that time comes around.

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