Agh, I hate those things! We're they like... Little worm-like larvae, and the adults are tiny, round, shiny black beetle-looking insects? I'd find the adults clinging onto the roots right at the top of the net pot, and they'd crawl up the stalk and fly around annoyingly. I tried soaking the res in bleach, in H2O2...and they survived! I removed the plant, and put it in an empty bucket, to let its roots dry out a little, hopefully killing some larvae. I soaked the res with room temperature water and regular old dish detergent for 30 mins, rinsed, scrubbed, filled it up again with the water and soap, super bubbly, and let the plants roots soak in it for another 30 mins. Rinse well, clean air stone with H2O2 soak, wipe down tubing with alcohol. Set up DWC bucket again, with just plain water... It seemed to really help. I have also tried the mosquito dunks on a plant I was gonna trash and not smoke anyway with great success... I wonder if it would have been ok to smoke tho?