Why Hydroponics Fail: 8 Common Mistakes Growers Make

People enter the world of hydroponics for many different reasons, these can be for fun or profit, and in both avenues, it will pay to know what you are doing before you make any form of investment. Like any form of gardening, the more you do, the more knowledgeable you become and the better you are at knowing the requirements and complexities of growing plants in a soilless environment.

It does take an abundant amount of planning and research when starting, and by doing so, you can save on making several common, time-consuming and costly mistakes. These are unfortunately made over and over again by new growers.

Here we will take a look at the top 8 mistakes made by hydroponic growers, and hopefully, you can use this information to avoid making the same mistakes in your hydroponic venture.

Why do we focus on hydroponic mistakes and failures?

There is a learning curve when first starting out in hydroponics, and it is a curve many individuals might try and take shortcuts or rush, rather than taking their time and correctly doing things. We focus on these common mistakes because as humans, we learn more from errors and failures than we do if something is running successfully.

We can also take these mistakes and use them as opportunities to learn and improve our hydroponic systems, from the first beginnings to scaling up operations. There will still be hiccups along the way, but knowing what the most common areas for failure and mistakes, go a long way to making your hydroponic venture a success.

Mistake #1: Grow Space and Hard to Use Systems

Although a hydroponic system can be set up in almost any location, this is no reason to think any space is suitable. This is one thing which catches many growers out because they design systems which become hard to manage.

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When a system isn’t designed with the growing space in mind, things like workflow and efficiency are often forgotten. This leads to growing areas that:

  • Use space ineffectively
  • Are difficult to harvest
  • Can require lots of tending to and transplanting
  • Are not ideal for pest control
  • Access to vital components is difficult

These can vary if you are growing indoors or utilizing a greenhouse. However, all variables need considering before you build your system. This can fall into two categories, growing needs being one, and user needs being the second.

Growing needs

  • Lighting
  • Watering
  • Nutrients
  • Pest control
  • Heating & humidity

User needs

  • Access
  • Convenience
  • Automation
  • Redundancy

A prime example being growers who design systems in a basement. They have their nutrient reservoir sat at the side of their grow table, and when it comes to the time of flushing a system, they have no means of draining their reservoir without the use of a bucket.

Mistake #2: Underestimating System Build Costs

For home growers, a hydroponic system can be built for as little or as much as you want to spend on it. Underestimating these costs regardless of system size can leave growers out of budget, and with a system, they are unable to use.

Different system types do cost varying amounts of investment. Some systems can even be built without the need for purchasing certain production items and using products from local hardware stores. Grow towers and NFT systems being good examples.

Following on from mistake #1, it is better to fully design your system and calculate costs before you being installation.

Mistake #3: Choosing the Wrong Crops 

Thinking every crop will grow the same in every type of hydroponic system is one quick way to failure. Not only do all plants have different needs, but some also are not suitable for specific environments. Growing indoors, or outside in a greenhouse or other growing space will have a distinct bearing on this, but, there are three quick questions to ask yourself before purchasing any seeds to grow in your systems:

  1. Are you facing any climate constraints?
  2. What are your growing techniques?
  3. Can you grow the desired crops with your production techniques?

All crops come with very different needs. There are tall plants and short plants, and all these can only be cultured in a certain way. If you are using a raft system, then there is no use in looking to grow tomatoes as an example.

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Climate is also one limiting factor. If you are battling against high heat, then you have little chance of growing cool weather crops, and vice versa. Unless you can control temperatures affordably, there is little reason to attempt growing crops that stand a good chance of failing before you begin.

Mistake #4: Ignoring PH Levels

The first three mistakes can all be attributed to setting up a system before actually growing. Now we are at the stage where plants are at risk when things go wrong. This is one of the most crucial areas of any hydroponic system, and it happens to be one area which is often ignored or mismanaged.

This mistake stems from growers wanting to see results as fast as they can and mix up nutrients and begin watering their plants. The urge for results prevents growers from even considering all the formulas and acronyms they need to know, and the effects of what comes with them.

Knowing about PPM, pH, 18/6 and others can be overwhelming, but they do play an important role. Many of these terms can be somewhat ignored, but pH definitely can’t at any cost. When pH levels are out of balance, it is the plants that will suffer, and they can suffer faster than many growers fully understand.

pH determines when nutrient solutions or plain water are acidic or alkaline. Ordinary tap water has a pH level which in most cases is suitable for use in hydroponic systems. Growing media in most cases is already pH balanced, although something such as Rockwool is more alkaline than other growing media such as coco coir.

pH neutral is a level of 7.0, which is what most soil grown plants prefer. In hydroponics, you tend to find plants prefer a little below this level and have a range of 5.5 to 6.5 depending on the plants in question. Many nutrient deficiencies come from pH problems, so making sure these are in check is vital. You can be chasing issues in other areas, and gaining no ground in solving them because your pH is wrong.

Both a pH testing kit and also pH adjusting compounds are advisable, so you can quickly adapt your nutrient mix to the correct level (check on a daily basis). Once you do so, your plants can take up all the nutrients they need.

Mistake #5: Using Too Many Nutrients or the Wrong Nutrients

Not all fertilizers are the same. First off, conventional fertilizer won’t dissolve entirely and can quickly block pumps and pipes. Additionally, they don’t contain the same nutrients as a good quality hydroponic formula.

With the correct nutrient solutions in hand, you then need to make sure your mixes are at the proper levels. The addition of too many nutrients is way too easy, and it is a mistake a vast number of growers make way too often.

A lot of this problem is not always the fault of the grower, some of the blame is down to the company supplying the nutrients. These nutrient companies often include feeding schedules with their products. Unfortunately, these feeding schedule dosages are set too high.

This quickly leads to nutrient burn (nute burn), and although it doesn’t kill your plants, it will have an impact on how they grow from that point forward.

To overcome this problem, you can follow the same feeding schedule which comes with your nutrients, however, cut the dosage to a quarter of what is recommended.

An example being, if the guide is for 2 teaspoons of nutrient solution per gallon of water, only use 1/2 a teaspoon. By doing this, and your pH levels are in range, you will quickly see if there are signs of nutrient deficiency. If this is the case, you can increase the dosage up to half of the recommended dosage per gallon.

Following this methodology, you can also cut down on the salt buildup that occurs when your nutrient mix is too rich.

Mistake #6: Watering Too Often

Most of us were raised to think plants need sun and water every day. When this attitude is coupled with growers wanting to provide everything for their plants, they often end up overwatering their plants.

This overwatering can cause plants to droop, and in extreme cases, it can cause plants to suffer from root rot and die. If you can catch it in time, you can make adjustments to your watering, and plants can restore themselves to their full glory.

The climate or growing environment can affect this, and you will need to allow for external temperatures and evaporation. One easy way to tell if you have your watering schedule set correctly is to test the top inch of your growing medium. Using coco coir as an example, if your finger pulls away dry and there is no sign of moisture, then it is time to water your plants.

When using a hydroponic pump, it will take some trial and error to find the best balance, depending on your system.

One thing which is worth noting is for DWC (deep water culture) systems is to make sure you have sufficient air stones in your solution. Overwatering is basically a plant being deprived of oxygen, so you can have everything set correctly, but without oxygenating your solution, you are in effect overwatering your plants.

Mistake #7: Not Enough Light

This can be seen as the second most crucial area in a hydroponic set-up. Growers who don’t choose to invest correctly in their lighting rig, more often see their systems fail, or at least they don’t deliver on the yields they receive.

You can easily make or break your hydroponic garden by ignoring the importance of lighting. Here are three reasons getting it right can make a world of difference:

  • Buying too little (small or low power) lighting solutions, and your plants will suffer
  • If you purchase the wrong blubs, then your plants won’t grow
  • If you decide on the cheapest options for your lighting, they might not perform

Lighting will be one of the most critical investments growers can make for their systems, so it is vital some research is carried out to see which is the best solution for your growing space, and for the plant types you are hoping to grow.

Fluorescent lighting: Many growers are led to believe these light types are suitable for all plants at all growth phases. They are also attracted by their low price.Unfortunately, these types of tubes only emit a kind of light. White light doesn’t deliver the full spectrum of light needed by plants at the different stages of their growth.

Fluorescent lights are ideal for your seedlings, but once these enter vegetative and flowering stages, they need all of the blue, red and orange parts of the spectrum.

HID Lamps: these are among the top choice by many serious growers. They also come in two varieties HPS (High-Pressure Sodium) and MH (Metal Halide) and are often seen lighting large areas, such as streets or parking lots.

Although bigger, they are actually more efficient than regular light bulbs. These bulbs also come with a mechanical or electronic ballast that has the function of starting and maintaining the arc in the lamp. These lights do produce lots of heat and are often found inside ventilation chambers.

A good rule of thumb is to hang your lights around two feet from the top of your plants, and to find if this is ideal, put your hand on the top of your plants and see how hot your hand is. If it is too hot for you, then it is too hot for your plants.

LED Lights: These are new to the world of hydroponic lighting. Being energy efficient, they are powered by an external power supply. This power supply in most cases fails before any of the LED grow lights do, but it can be quickly replaced.

LED’s produce less heat and deliver a unique light spectrum that is conducive to photosynthesis.

Choosing the right lighting

When looking at your lighting options, there are a few factors which need looking at. These include budget, enclosure type, ventilation, and plant types.

Low budget growers can opt for regular fluorescent tubes (T5 type) while small-scale growers are better suited to use the newer compact fluorescent tubes. Once you have a more extensive system, you can then opt for the HID lighting systems, but because of their heat output, you need to check ventilation, and also your feeding times might change.

Ventilation also needs to be away from your grow room, cooling costs will increase, and it will be hard to regulate temperatures.

At present, LED’s are left for long-term growers, but over their lifetime, they will save thousands of dollars in electricity bills.

Mistake #8: Sanitation, or Lack of It

One final mistake many growers make is sanitation in their growing area. Because hydroponic systems are a sterile environment, this extends to the entire area, and not only the systems plants are growing. Once there is an element of disease anywhere in a system, this can quickly spread and affect not just one or two plants, it will affect all of them.

Floors should be clean and dry, and all the tools you might use should be for the sole purpose of your hydroponic system or cleaned thoroughly before use. All this is before you even consider the condition of your systems.

Nutrient reservoirs can have algae buildup over time, so when you flush your system, these should be inspected and cleaned as required. The same goes for piping and grow beds.

There will be salt buildup from your nutrient mix, and this will cling to pots, and your growing medium, and if these are not thoroughly cleaned, it can exasperate problems when you add your next batch of nutrients.

Plant waste can be one of the most crucial, and as soon as you see signs of a problem, this plant should be removed as quickly as possible, because any diseased plant will pass it onto the others.


It can be too easy to say it is common sense to avoid making these mistakes. But, this is not the case, and no matter how careful you are, there are elements which creep in you might be unaware of. All growers do make mistakes, and in many cases, it is not through lack of trying.

There are a vast number of variables at play in a hydroponic system to have it running effectively at all times.

Hydroponics doesn’t have to be difficult, but learning everything can be overwhelming while you are first learning. Hopefully, you can use all the information above to design and implement a well-functioning system that can bring you hours of happiness and bundles of healthy plants.

I am a gardening and tech enthusiast! Stumbling across the world of Hydroponic Gardening, Aquaponics, and Aeroponics by accident I've decided to create this website to put all of the best information I can find in one easy to navigate place. I'll continue to add more content as I discover new things!

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