Something killing my plants!

Lower leaves turning yellow with dark spots. also have little gnats all over the plants, don't know where they came from. I hung fly strips I read in a book said to use a lite vacuum cleaner and remove them? But it's the leaves too much water?

I don't know if the leaves is the result of the gnats, all I can say is that after my gnat problem which I solved with h202 and relocating the tent, I had similar looking leaf damage. One single gnat can lay 200 eggs and if you are growing in soil, they thrive especially in damp conditions.

If you have gnats then they are what's killing your plant.. Not something lol

U may need to give a lil more info & maybe a pic of the whole plant so we can see size (pot/plant)...I have a black russian vegging that had leaves start to look that way when it out grew the small pot it was in.

Fungus gnats eat organic matter and maybe fine root hairs; it would take a sizable infestation to kill a mature plant although seedlings and small clones could be affected. You might have gnats or some other flying insect, but you also seem to have some other issue(s). Picture of the whole plant and details about the environment would help us help you better.

Fungus gnats in soil can be treated\prevented with Bacillus thuringiensis or Bti bacterium that produce a toxin which will kill gnat larvae. Bti is now more commonly available in liquid formulations, even from Lowes\Home Depot. Bti kills mosquito larvae as well and that was its original commercial marketable indication; Mosquito Dunks can be found everywhere if you can't get a liquid formula, break up the puck and soak about a quarter of it in a gallon of water for 12 hours or so, then water.