Best practices to Prevent Root Rot In Hydroponics

Now, when it comes to plants, their leaves may do the food-making job, but it’s actually the roots that provide them with the necessary raw materials. In hydroponics, where plants grow in water instead of soil, the roots play a crucial role in absorbing nutrients.

If everything goes smoothly, it’s all good. However, sometimes things can go awry if the conditions aren’t right, and one of those complications is root rot. But don’t you worry, I’ll break it down for you and give you some tips on how to prevent root rot in hydroponics.

Even if you’re a beginner and have no prior experience with hydroponics, this article will be beneficial for you. So, let’s dive in and learn how to keep your hydroponic plants healthy and happy!

What is Root Rot?

As the name indicates, hydroponic root rot is a disease in which the roots of plants are damaged. Unable to absorb the nutrients effectively, the plants do not grow properly. Therefore, the symptoms of root rot appear on the leaves as wilting, withering, or yellowing.

It is essential that the grower keeps inspecting the plants’ leaves and roots to ensure that they are disease free.

Symptoms of Root Rot

Root rot symptoms
Root rot symptoms

Symptoms of root rot can be seen with the naked eye, even in the starting stages. Following are some of the major symptoms that appear as a result of root rot.

  • Wilting of leaves
  • Yellowing of leaves
  • Root decomposition
  • Foul smell
  • The appearance of slimy material on roots
  • Discoloration of roots
  • Less than normal nutrient uptake by plant

How Does Root Rot Occur?

Root rot in typical plants is caused by continuous exposure to damp soil and moistness.

So, root rot must occur in all hydroponics, does it then? Certainly not

In hydroponics, water is constantly moving, and moving water absorbs oxygen. The stagnant water becomes a breeding ground for different microbes that cause root rot. Moreover, the resistance of plants gets weaker due to lack of oxygen.

Root rot occurs when roots don’t have enough oxygen to breathe. The lack of oxygen along with the presence of certain microbes is the cause of root rot in hydroponics.

Here are all the reasons that can cause root rot

  • Poor Aeration
  • Unclean Water
  • Nutrient Concentration
  • Contaminated Instruments
  • High Temperature

It is now certain that there are other factors that, when accompanied by wetness around the roots, cause root rot.

Those factors are actually the presence of infecting microbes such as certain bacteria and fungi. 

Fungi like Pythium and Phytophthora infect the roots and damage their structure, hindering or even completely blocking the absorption of nutrients.

However, these microbes cannot grow in well-aerated spaces. The lack of oxygen in the soil or water helps these microbes grow and infect the roots.

Choose the right system

There are a lot of different types of hydroponic systems with different characteristics. Generally, a system where roots are not in constant contact with water is less prone to root rot.

Based on this, the following are some system and their susceptibility to root rot.

Hydroponic System TypeSusceptibility to Root rot
Nutrient Film TechniqueLow
Deep Water CultureVery High
Ebb And FlowMedium
Hybrid SystemsHigh
Wick SystemHigh
Susceptibility of Different Hydroponic Systems to Root Rot

How To Prevent Root Rot In Hydroponics: practical tips

Having understood the causes and reasons, now it’s time to look for methods to prevent root rot in hydroponics. Here are all the ways to ensure that your plants grow healthy and hardy, with strong roots.  

Use Proper Watering Techniques

One of the major reasons why water contents lack oxygen is poor watering practices. Those practices include

  • overwatering
  • unclean water usage
  • not changing the water for a longer time
  • not monitoring any changes in water. 

Overwatering – while keeping the oxygen amount the same, can lead to stagnant water and a lack of oxygen. These conditions are ideal for pathogen growth that cause root rot. 

underwatering – can harm plants by making them weaker and less resistant to potential threats. Therefore, you need to look for the optimum amount that your plant needs to thrive. 

Unclean water – can contain the microscopic spores of several fungi, including the one’s that cause root rot. Always ensure that you use clean water free from all pathogens and contaminants. 

Contamination can also arise if you do not change the water for a long time. It is ideal to change the water after every 2–3 weeks. Here is a complete guide on how often you should change water in a hydroponic system

However, keep monitoring the tank. If you see anything abnormal like some green specks or slimy material on the roots, then change the whole water, and remove the infected plants. 

Monitor and Adjust pH levels

Maintaining the right pH level is super important for hydroponic systems.

The pH scale goes from 0 to 14, where 7 is considered neutral. In hydroponics, most plants prefer a slightly acidic to neutral pH, usually around 5.5 to 6.5. When the pH goes too high or too low, it messes up the availability and absorption of nutrients that plants need to grow.

This throws off their defense mechanisms and makes them more vulnerable to root rot-causing pathogens. So, keeping the pH within the right range is crucial for healthy plants and to avoid root rot troubles.

Ensure Sufficient Oxygenation

Lack of proper oxygen and insufficient oxygenation are major causes of root rot. In soil plants, the air is provided by little space between the soil particles. Those spaces contain oxygen and make the overall conditions unsuitable for the growth of pathogens. 

In hydroponics, this needs to be done artificially by air pumps. They’re similar to the ones you must have seen in the fish tanks. Yup, that’s all they do; add oxygen to the water. 

Sterilize the Equipment

If you have just ended up ruining a batch due to root rot and deciding to grow new plants in the same setup with the same equipment, then they will end up the same way, unless you sterilize them.

Fungi spores are microscopic, and even a single spore has the ability to infect the whole plant. Whenever you grow new plants, always make sure that you thoroughly clean the pieces of equipment with aseptic solutions. 

Treat with Beneficial Microbes

All pathogens are microbes, but not all microbes are pathogens.

Products containing beneficial bacteria and fungi such as Hydroguard can enhance nutrient uptake and protect against harmful pathogens.

This is scientifically called symbiotic relations (partnership in which the participating organisms benefit from each other) and is really common in nature.

Each plant has different classes of bacteria that are beneficial for it.

Do Not Grow Too Many Plants In the Same Place

One of the worst things about plant diseases caused by pathogens is that they do not stop at just one plant. They destroy any plant, around the infected one, to which they can have access through any means. 

To avoid this, the solution is really easy. Grow a limited number of plants in the same water tank. Since the pathogen here will travel through the tank, it can only attack those plants that are in the same tank. 

Give Ideal Nutrient Solutions

Different plants have different nutritional requirements. Giving a general nutrient solution to all types of plants can have unhealthy effects on the plant. 

Giving a nutrient solution with high mineral contents to plants with low needs can contaminate the water, making conditions for the growth of microbe.

Similarly, giving low content nutrient solution to a plant with high requirements can make it weak and prone to root rot. 

Control Water Temperature

Harmful bacteria and root rot-causing fungi grow in the waters with temperature. By ensuring a low temperature in hydroponic water, the growth of such harmful microbes can be stopped. 

For this purpose, water chillers can be used. Though they are a little costly, they do ensure that no microbe infects your plants. 

However, if you are just starting out, I recommend not spending so much on this before getting your hand right on hydroponic growing. So, better use other preventive measures explained in the article. 

Remove the infected roots

Older roots are more susceptible to microbes attacks due to their reduced resistance. Therefore, keep the roots well-pruned. 

Keep monitoring the roots, and if you notice anything unusual such as wilting, darkening, or unique spots on the roots, then these are signs of some disease. Better to prune the sick part before it travels to the whole plant. 

The good thing about most hydroponic diseases like root rot is that they can be “prevented” by simple precautionary and preventive measures. Now, you better keep an eye out for the symptoms mentioned above in your hydroponic plants, and be a hydroponic medic for your plants to get the most out of your hydroponic journey.

Can I save a plant that is already infected with root rot?

Though you can save such a plant if detected in its early stages. You can do so by simply cutting off the damaged parts. However, I do not suggest doing so, as microscopic spores are too tiny to see and clean. They can always be on other parts and can infect later.

Can I use antibiotics and fungicides to kill microbes?

Yes, you can, but remember to use it as a last resort. The best course of action is to use preventive measures, and if still root rot occurs, you can always get rid of those infected plants, and replace them with healthy ones.

Can certain nutrients boost root rot?

Not really. All companies make hydroponics, keeping in view the nutritional needs of the hydroponic plants. All use the prescribed nutrient solution for your hydroponics, and there’ll be nothing to worry about.

What if I leave root rot untreated?

Then the plant will gradually die. There is no other way than to treat root rot if you want to grow hydroponics.

Are organic nutrients better at preventing root rot?

It does not really matter whether you use organic or inorganic nutrients for your hydroponics if you use them in the right doses. High concentrations of both organic and inorganic nutrients can increase the nutritional content of water, promoting root rot.

1 thought on “Best practices to Prevent Root Rot In Hydroponics”

  1. Thank you for all the hydroponic tips.
    I welded an A frame from steel, 1,6 meter high. Im starting with hydroponics.


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