I had fungus gnats like you wouldn't believe in my legal indoor garden in my house. I treated my cannabis as though it had an infestation just for good measure. I will say, though, that sand works wonders. Calling the problem an infestation would almost be an understatement. My sticky strips were probably catching about 10/hour when they were fresh. After about 2 weeks, they were saturated with no more stick surface left for more gnats. At any given time, each pot would have about 4 gnats per sq inch crawling around; really ridiculous.

I ran out of fly traps just as I decided I was going to lose all my plants if I didn't take action. I therefore got more sticky strips, but the night before I did that I covered all my soil surfaces with about 1/2" of sand. The next day when I set out the new strips, there was hardly a gnat in the air, practically no gnats on the leaves, and I wouldn't get a swarm crawling out of the soil when I watered. The fly traps half only been catching 3 or 4 per day since I added the sand about 5 days ago. We'll see how things work in the long term, but I think the sand pretty well put the brakes on their life cycle.
sinky Reviewed by sinky on . Spider Mites or Amblyseius Fallacis? I wish I could post the pics from my microscope. I was checking the plants this morning and saw a bunch of fat little bugs (smaller that an average speck of sand) crawling around the soil. I took a teaspoon of sand, put it on a plate, isolated one of the buggers from the sand particles, put the plate in the toaster oven until it stopped crawling, then put him under the scope. What I found made me think spider mite. I threw some loose leaf tobacco on top of the soil (actually on top of the 1/2" Rating: 5