Pioneering Hydroponics

Since 1976

5 Most Common Plant Diseases in Hydroponics - Part 1

We’ve previously mentioned how to treat Pythium in hydroponics, but are you aware of other common plant diseases that can affect your plants in hydroponics?

Learn how to diagnose your plants before it’s too late and learn how prevention can help save you (and your plants) from a lot of trouble.


Root Rot

Root rot is very common in hydroponics when there is poor water circulation. Water circulation is what influences the levels of aeration and oxygenation in plants; the less oxygen is available for roots to absorb, the higher the chances that your plants will develop root rot.

This can happen when water doesn’t infiltrate through the soil as quickly as it should, causing moisture to stagnate around the plants’ roots. Root rot can have a very unpleasant look and earthy smell, with roots looking slimy and brown.

If you caught the root rot as it just started, you can still try to treat your plants. With an advanced state, however, it can be easier to simply restart your crops. The basic treatment for root rot is to add beneficial bacteria to the nutrient solution so they can help fight the fungi and protect the roots.

We recommend a Roots Excelurator to help cure your plants. To prevent the issue from happening, you should:

  • Keep the roots healthy. The water in the reservoir becomes an ecosystem in itself, with a protective and beneficial biofilm layer forming to protect root mats from moulds and damage.

  • Keep the grow room temperature cool. This will help keep the nutrient solution cool, which will make dissolved oxygen more available to plant roots. 

  • Keep hydroponics equipment sterilised and clean. Whenever you have to dip a tool in the nutrient solution, you need to make sure it’s appropriately cleaned and sterilised to avoid the proliferation of harmful bacteria on equipment.


Powdery Mildew

Powdery mildew looks as if someone sprinkled a white powder over plant leaves and stems. When untreated, it leaves to leaf drop, stunted plant growth, and yellowing of plant tissue. Should it be allowed to progress too far, the plant will die.

Providing plants with higher calcium availability helps plants form a natural protection against powdery mildew. And any extra calcium that is unused is stored in a storage vacuole inside the cell.

We recommend Humboldt Sea Cal.

Prevention and treatment methods for powdery mildew are:

  • Avoiding high humidity levels. Moulds and mildews love high humidity environments, which also interfere with calcium uptake.

  • Avoid big fluctuations of relative humidity levels. Relative humidity should be between 40%-60%. Should powdery mildew grow on your plants, lower humidity levels can stimulate the fungus and make it produce more spores that will quickly spread.

  • Removing all infected leaves. As soon as you spot signs of powdery mildew, you need to carefully remove infected leaves to not spread the spores. The leaves need to be removed from the grow room and disposed of.

  • Providing optimal airflow. Stagnant air in the grow room leads to moisture building up on the undersides of the leaves. Calcium uptake is disrupted when transpiration is halted.

  • Providing silica to plants. Plants mobilise silica toward the point of infection to form a callus around the surrounding cells. Help your plants fight diseases by providing them with what they need to help prevent the disease from spreading.

We recommend a House & Garden Amino Treatment.

Grey Mould (Botrytis)

This fungus can spread very quickly and result in the loss of crops before you know it. It looks like a white to grey growth that turns brown with time. Grey mould spores can enter your grow room through the air, in which it will thrive due to the high humidity level and nutrient availability.

Once grey mould has established itself on your plants, it’s recommended that you remove the infected plants completely and dispose of them away from your grow room. You can reduce the risk of grey mould in your grow room by:

  • Removing all trimmings and dead plants from the grom room.

  • Reducing humidity and providing proper ventilation.

  • Regularly sterilising all hydroponics equipment.

We recommend Silver Bullet Mist to treat grey mould, Pythium, powdery mildew, and much more.

Stay tuned for part 2!