And so did everything else…Usually nematodes, hypoaspis miles, and rove beetle keep these guys in check. I used that and thuracide, microbe lift, mosquito dunks as well.
I finally found something that had an immediate noticeable impact and I want to use a Chem at this point since plants are only vegging I feel okay with this and wont be flowered for at least a month.
What do you guys recommend? Is there anything that will just ko’s these things? When I was using chems many years ago not much I found over the past 25 years really works. Hoping something new is around or maybe something old I never tried.
So the product that I used and made a huge difference so far is No Fly. This stuff actually made a difference from day one of use. I want a death knell now…I’ve only had it on them for 2 days now but it’s a big difference. It may be the only thing I need but I don’t want to find out this run. I’ll experiment next run.
Any suggestions are welcome. I also use a fogger with soybean oil, peppermint, citric acid etc but it just doesn’t do anything. I will add pyretrhins to it today and I am sure it will work then.
My favorite way to eliminate gnats when theirs a big infestation is to use a top dress that keeps them from accessing the soil. I like Gnat-nix (it’s glass stones that kill the gnats if they try to crawl through it).
Then as long as you use fabric pots (no drain holes at the bottom) the gnats have no way to access the soil.
They sell little screens you can put over the drain holes on plastic pots but it’s a PITA.
I am usually able to keep them in check with just yellow sticky traps (I like the smaller ones with the pointed ends that you can just stick directly into the soil), and if I start seeing a bunch I water with BTI ( Bacillus thuringiensis israelensis. Same thing that’s in mosquito dunks, but I like buying the powdered versions vs mosquito dunks which are meant to slowly release) which eat the larvae in the soil.
I don’t see a reason to resort to harsh chemicals for gnats.
Edit - I also like to have fly paper rolls hanging. They catch a lot of gnats.
I personally think gnats can be defeated by backing off watering. If you have gnats then it’s a sign that your medium is too soggy.
A fan beneath the canopy and above the soil will prevent them from flying around and reproducing. If it’s bad… Like, really, really bad, you can use a diluted hydrogen peroxide drench in the soil. It will nuke them as well as all the other biology in your soil. Good and bad.
I’m really not a fan of heavy measures for gnats. Especially pesticides. Never use pesticides for gnats. They’re a sign that something else is wrong.
I forgot to list everything I used…thuracide + dunks like over a week ago. Seemed to have almost no effect this time. It really put me at a loss. They were partying in it and seemed to rolling in the DE for fun…
A good bti product used consistently to keep larva in check, a soap / isopropyl spray to kill adults and a 1” layer of sand on the surface of pots will knock out a bad infestation.
Yeah I used it. Been using it for years. Maybe I just need to wait longer but they just totally blew up a few days after adding everything. It was in soil that had coco in it. Pretty sure it was the coco they used. There’s no entry point for them so at least it’s contained but man it just seemed nothing had effect. Lost a lot of valuable seedlings. Should have just made my own soil like always.
Yeah, something to keep in perspective about gnats is that they’re mostly just annoying and don’t cause major problems aside from eating seeds and seedlings placed directly into the soil. I’ve got roly polys, centipedes and worms, too.
lay out some traps for the adults.
works really well. 
