What does Fungus Gnat Damage Look Like?

I still cant figure out whats wrong with my plants on my second/3rd indoor grow. Thought it was my nutes, or my hard tap water. But seeing the problem again. Necrotic leaves dropping easily starting at the bottom. Halfway thru flower. It is pretty shady at the bottom of the canopy, but doubt thats it.

I have a pretty bad fungus gnat problem. And the more organic controls I try to water in, the more I end up making nice wet soil for them and they never die! Probably cus the Bt and crap only kills for a few days, so it doesnt cut the cycle. So I hung a no pest strip and went for the big guns a few days ago. Think its helping, I havent checked, but I hope theyre all about dead today. Could they be killing my mature plants? I am able to clone decently still. I could see them taking down clones, but mature plants? I see people claim it happens.

Gnats can and will kill a plant if you cannot control the problem. The larvae feed on the plants roots until it develops wings and will fly around aimlessly until it finds a place to lay for more eggs. They lay some ridiculous amount of eggs, like hundreds or a thousand, easy to see how the population grows so fast. I have a small problem that started about two months ago in one of my rooms. As soon as I noticed it wasnt just the usual one or two that somehow find there way in, I bought the yellow sticky traps that they fly on and get stuck to. Also you can put a plate with vinegar on it, they will attractted to the smell and will drown before they can get out. I did not do this because I was afraid it may attract more into the room. My problem has gotten worse over time, slowly with the traps. It is a little bit of a concern for me at this time but then again time is on my side as I am cutting them down friday. Also you should take out about a 1/2 inch of soil from the top of your pot and put fine sand in. This will help prevent the adult gnat from being able to lay eggs. They have a video on youtube that shows this exact process.

Good luck with those turds...

Oh, I meant to tell you I am not sure the actual signs that the plant will show due to damage from gnats. Never got that far, fortunately.

I put four of the sticky strips in my 10x6 room. Hung two by the door, and put two more under my areoponics table on the ground.

Ever hear of root aphids? I saw a big rant about them. I saw a few tiny bugs that looked like them.