Fungus gnats

What others said will work. I found that watering habits are the biggest contributer to gnats. You can also put a bowl of water with a drop of dish soap in it on the floor of the room. They will drink themselves to death as the soap gets on the wings and they can't get away and drown. Won't do anything for larvea in the soil, but kills a lot of adults. Best of luck, Happy Growing!

Best way to control them is adjust watering practices. Can also use yellow sticky traps. Helps attract the adults due to their color, helping to reduce their numbers and interrupt their life cycle. Introduce beneficial nematodes or use products containing Bacillus thuringiensis israelensis (BTI), which specifically targets gnat larvae without harming your plants. You can mix crushed mosquito bits with water and apply this solution to the soil. Lastly Sprinkle diatomaceous earth on the surface of your soil. This natural powder is harmless to humans and pets but acts as a desiccant that damages and kills fungus gnat larvae upon contact.

I'm a fan of Nematodes for soil and BTi for soilless. bother work though. Adding a thick later of sand of anything on top of the medium can also work but weights it down and take up space for medium it can grow in. Controlling you watering habits can help a bit but won't knock them out 100%. This is a very common problem with a very simple fix. BTi or Nematodes. can order products to treat it online or in person at grow shops.

SF nematodes to kill larves and sticky traps to kill the flies. But unless there are like 1000, it wont your hurt plant

Mosquity bits or dunks. If that product isn't in your region, something with "Bti" or 'bacillus thrugeniss (israelis supspecies)" -- i definitely spelled that wrong, but it'll be recognizable. It's a bacteria that will kill most larva in soil/solid substrate. It's a bacteria that;s been used on the world's food crops for a century? i.e. it is safe to use. larva often comes from the store when you buy a substrate. so using this stuff pre-emptively is a smart thing to do. If you see no hint of gnats after a few weeks you can stop. I leave a dunk in my resesrvoir for the entire grow. mid-problem, it'll takes 3-4 weeks to get it under control by itself - basaically an entire lifecycle of time and a bit longer. In the meantime you can also use sticky traps and if not in flower, a pesticide-spray becomes an option, too. The adults don't damage anything, so they are annoying but not what is hurting your plant. The larva is chomping on the roots. Killing adults reduces reproduction, which is good, though. Either way, it'll take 3 weeks or more.

Yellow sticky traps.. Lady Bugs..

Also putting sand and rocks on top of the soil helps keep them

Hey there I have had the same problem a couple times one time they were bad in my crop and then they moved over to my seedlings so I just tossed my seedlings and all the dirt I had and cleaned the grownroom really good and waited 10 days to buy new soil If this is not an option then read below 1st thing is you gotta start letting your soil get really dry in-between watering 2nd when you do water add hydrogen peroxide 1 part hydrogen peroxide 5 parts water do this one time make sure the water solution gets all the way thru the soil 3rd get a couple boxes of yellow sticky traps off amazon there prob like 5 for a box of 5o. Then for every 1sq foot in your grow put a yellow sticky trap and change them out every day or other day The combination of these things should get rid of the most of them I can't garentee you can kill them all without a complete cleaning and 10 days wait. I would suggest after this harvest that you toss any reminder soil you have and clean and waot 10 days and start over.i can almost garentee they will make there way to your next set of seedlings and it starts all over. There is always 1 that makes it somehow Good luck and the good thing is if you get a good amount of them killed before harvest not that many will be stuck to your buds I've never had a problem with them ruining the actual buds by being stuck to them but it is annoying to see them all over the places Again good

Fungus gnats are more a nuisance than anything. In heavy concentrations the larvae can hurt roots but they're mostly harmless. They breed and feed at your substrate, that's where you wanna target them. Sticky traps will catch adults but you wanna interrupt their life cycle. Many on here preach nematodes but that takes awhile IMO, I like diatomaceous earth. It's like razor wire to small insects and it's food grade safe for people. The main thing for controlling gnats is not fostering an environment that they like. Don't keep your media so wet or topdress with something that's not gonna grow fungus.

I always used nematodes and it worked. Some say they dont tho ... ;) Sticky traps is a must anyways.