I'm so excited about finding something that works to kill fungus gnats!!!
I have been searching for a few days and this is what I have found. Many people use sand to top their dirt and that seems to help but I don't want sandy plants. I read about hydrogen peroxide mixed with water so I experimented. I put 3 fungus gnat larvae in a glass and added the H2O2 mixed with water. They looked fine.
Like they were swimming when I expected them to appear to be in great pain, wiggle and stuff.
So H2O2 is excellent for aerating the soil and I will do that every now and then but fungus gnat larvae were fine. (I watered all my plants with mix and checked them the next day and the larvae were fine
Ok so I found the perfect solution!!! It's called Beneficial Nematodes!!!! They are tiny little microscopic worms that eat fungus gnat larvae as well as any other larvae for breakfast lunch and dinner!!!
They have a video on YouTube about use of the beneficial nematodes in greenhouses and it's all they use. They put it everywhere since it's safe for humans and animals. There is a short clip in two of the ones I watched where you can see a fungus gnat larvae being eaten alive by the BN!!! It looks awesome
I looked online and you can order them from Home Depot for $13 with gives you two treatments. (You just mix the BN with water and water them once and then again 7-10 days later a second time). I suppose you would want to not water your plants for a few days prior to receiving the BN so the soil is ready for a good BN watering. I am super excited to get mine!!!
I would suggest maybe watching the YouTube vid of the greenhouse use because it really shows how to mix it up with the water carefully and store the BN in a colder temp because they are alive and if you kill them before you water your plants with them ... It won't work bec they are dead lol.
I have to say I jumped the gun last night before I found out about BN and I took away all my houseplants soil and put them all in water. I was just so fed up with the evil little things!!!
Since you have to mix up the BN with water I will just repot the plants and water with BN water. ((Also the H2O2 mixed with water (1 part H2O2 4 parts water I think) kills the ugly looking fungus that forms on tops of houseplant dirt. So that looks much better as well as killing a source of fungus gnat food. But you still need the Nematodes because the FG will just eat roots instead.)) I will let you know how it works!!!