tiny knats? in nute water

I am seeing little tiny bugs that I think are new hatched knats mostly floating on top of the water. If the buckets were not black and the light bright I don't think I would see them at all. I'm wondering if anyone has a similar experience? I don't think they are aphids, but I don't know what root aphids look like.
I am flushing them out of the buckets and have been doing extra flushing of the system, but they are hard to irradicate. I'm wondering if a filter on the pump could help remove them. I have a lime tree outside that I am treating as well as it is near the air vent.
I'm wondering what effect they will have on the roots? I don't see them on the plants or in the air. I am growing g-13s in 4th week of flower in ebb and flow.
Thank you for any suggestions.

Ive had fungus gnat problems in the past and sometimes I would find them floating in my res. Inspect your roots. Do you see little tiny worms crawling around? They are the larvae. Theyre very small but can be seen by eye. Use Azamax in your res, it will kill all the adults and larvae but not the eggs, so use azamax again in about 5 days to kill the rest once the eggs hatch. I use mosquito dunks as well, wrap it in a nylon and just leave it in your res at all times.

Ya have to shoot for no,light in the root area.H2O2 is the shit for slime and mold too.Do a little research I cant tell ya where your screwing up without more info but you can find out with a little bit of looking around.Good luck man.

Yeah i just had larvae problem in my nute water and my plants werent growing.. i got that azamax yesterday and they look good so far.. roots are alot cleaner.. smells kinda good too, organic... but you deff need H202 to keep clean! and NO LIGHT!