They sound like gnats. Try setting some sticky traps on the rim of your pots. That's what I do and it controls them pretty well. I'm using coco, run to waste, same as you. :thumbsup:

PC :smokin:
PharmaCan Reviewed by PharmaCan on . Little flies on coco Using coco with run to waste. Have noticed these small flies that seem to run round the rims of the pots. Put up sticky pads and caught quite a few around the ceiling. Looked at them with a glass and they are small and black with wings, long and thin about 1mm long. Cant notice any damage on leaves or anything much underneath. Had them for a few months now. Been offered soem systemic spray that is pretty nasty stuff that will do the job but am in 4th week of flower so am reluctant to spray Rating: 5