Killing Fungus Gnats In Hydroponics

Sharing is caring!

Last Updated on February 21, 2023

One of the most common annoying pests that can frustrate your hydroponic garden is fungus gnats. If you are looking for solutions to killing fungus gnats in your hydroponics garden, we have the answer for you here.

These repugnant pests are usually seen flying around hydroponic gardens be it in an indoor garden, houseplants, or greenhouse. They can reproduce so rapidly and the females are capable of laying up to a thousand eggs. They are also known as fungus gnats because they can infect your plants with fungal disease.

Both the adult gnats and their larvae are perilous to the health of your plants. Therefore, getting rid of these troublesome flies is crucial to avoid infestation of your garden.

What are Fungus Gnats

Fungus gnats are flying pests that can infect your garden with fungal infection. A female gnat can lay hundreds of eggs at a time and they love to lay eggs in damp or algae environments. They can be found flying and walking about on your grow medium and the base of your plants.

Adult fungus gnats will lay eggs that will cause havoc to your garden. It is their larvae that will feast on your plant roots system and eat away and exposing your plant root to pathogens. Gnat larvae will chew deep into your plant root in turn cause stunted growth, loss of foliage, and discoloration of leaves.

Fungus gnats are common pests to plants such as cucumbers, peppers, mushrooms, wheat, clover, lettuce, soybeans, alfalfa, Potato, and corn.

A garden that is seriously infested with gnats will display symptoms of nutrient deficiency because the root system has been impaired.

Killing Fungus Gnats In Hydroponics

Taking control of the situation is very important when your garden starts to experience fungus gnat invasion. So, here are the various methods you can use in killing fungus gnats in your hydroponics garden:

Biological Method Of Killing Gnats

  • Hydrogen Peroxide: an effective way in killing fungus gnats in your hydroponics garden is to use 3 percent hydrogen peroxide. Dilute 3 percent hydrogen peroxide with water. Make use of 2 tablespoons for one gallon. We recommend you start by using a little portion for the first one or two weeks then increase the portion afterward. Even though hydrogen peroxide is very effective, it can burn your plants. Therefore, use them with care. However, we recommend you other methods before you settle for hydrogen peroxide. If other methods fail, then you can try using them.
  • Commercial Products: there are several commercial products to use to killing fungus gnats in your hydroponics garden. They are pretty effective just make sure you follow instructions and your hydroponic garden will be good to go.

Bonide (BND951) – Systemic House Plant Insect Control, 0.22% Imidacloprid

Natural Method Of Killing Fungus Gnats

  • Sticky traps: sticky traps can be used to catch and kill fungus gnats. If you can kill them, you have the chance of preventing them from laying eggs, thus reducing hydroponic garden infestation.
  • Vinegar: put some vinegar inside a jar. Fungus gnats are usually attracted to the sweet-smelling vinegar. You can cover the vinegar jar with a thin cover and puncture a hole or two. They will fly through the jar holes to reach the sweet-smelling vinegar and eventually drown.

Preventing Fungus Gnats Problems In Hydroponics

Preventing the future occurrence of fungus gnats will go a long way to keeping your hydroponic garden healthy. Here are the ways you can prevent fungus gnat infestation:

  • Shut all doors and windows in your hydroponic garden. Fungus gnats can gain access to your indoor hydroponic garden by simply flying in through your windows or doors.
  • Double-check any new plants (be it clones or transplanted plants) you may want to introduce to your hydroponics garden. A single fungus gnat eggs infected plant can wreak havoc to your hydroponic garden.
  • Between watering, allow the upper part of your plant to dry out before you water again. Therefore, you should maintain a dry environment at the top part of your growing medium. This will discourage fungus gnats from laying their eggs as they like damp areas.
  • Remove any access to fungus gnat food source by getting rid of any dead plant matter or algae.
Preventing Fungus Gnats Problems in Hydroponics


How do you kill fungus gnats in DWC?

The best way to kill the gnats is to spray them with a solution of bleach and water. I have been using a solution of one part bleach, three parts water for years, but recently started adding a few drops of dish soap as well.

How do you keep gnats out of hydroponics?

The only thing you need is something to cover the top of the tank with. If you have a larger tank you can use a fan to blow the air out the sides. I have used a "gnat trap" on my last two grow's. It is a piece of plastic tubing about 3 inches in diameter. It's placed at the bottom of the tank.

Where do fungus gnats come from?

Fungus gnats (Diptera: Tephritidae) are common pests of flowers, crops, and trees in many parts of the world. They are among the most common insects found on plants. The most common species are the European red mite (Panonychus ulmi), the American red mite (Panonychus citri), and the Asian citrus psyllid (Diaphorina citri).

These three species are considered to be the most important insect pests of citrus fruit. All species of fungus gnats are blood-sucking parasites of living plants. Females lay their eggs in the soil or on decaying organic matter near plant roots, and larvae emerge as adults in two to four weeks. Adults feed on a variety of plants, including trees, fruit, and vegetables. They can be difficult to control because they are often very abundant in infested areas and will breed rapidly under favorable conditions. A wide range of pesticides may be used to control these pests. Commonly used products include insecticides such as organophosphates, carbamates, pyrethroids, and chlorinated hydrocarbons.

How do I know if my plants have fungus gnats?

Many people don't realize that the common housefly is a fungus gnat, which has a similar appearance. Here's a great way to find out: If you see flies buzzing around your garden or in your home, then it's probably a fungus gnat. In fact, many people are more familiar with this pest than they are with the housefly. They're small and brown, and they have two long legs. And most importantly, they bite!

Here's another fun fact: The housefly will eat fungus gnats. When you see them flying around your garden, you can usually hear them chirping. But you'll also notice that the housefly is more attracted to fungus gnats than it is to other insects. This means that when you see the housefly fluttering around your garden, it's probably trying to help out by eating fungus gnats!

How do you get rid of fungus gnats naturally?

You can try using sprays and traps to bleach and alcohol. What really works to spray a diluted mixture of soap and water. It kills them before they have a chance to reproduce.

Additional Information

It is pretty common to have fungus gnats issues among hydroponic growers. Therefore, the key to beating this problem is to act fast as they can be easily controlled.

The victim that suffers from fungus gnat is mostly indoor gardeners, be it home or greenhouse. Outdoor garden fungus gnat issues are usually controlled by seasonal weather changes and natural predators that feed on them.

Ensure you follow our preventive measure tips to avoid fungus gnat infestation in your hydroponic garden.

Sharing is caring!