Want some advice?
These are probably Fungus gnats. They arrive in plants from Wally mart or other nursuries and live/lay eggs in the soil.
If you see gnats, then they have alreadfy laid eggs in your soil and larvae are on the way. The eggs then go into larvae stage..and then hatch to flies and lay eggs and it goes on over and over.
What ya wanna do is this. Find those "mosquito dunks"...the round/doughnut lookng things you float in lakes/ponds to kill skeeters/larvae..etc. It's got baccillus isrealisis in it...and THAT will just fuck em up seriously. you soak the dunks in 5 gals of water for 24 hours..then take 1/2 of the water off (or whatever you use to water)...add yer nutes..and water yer plants with it, making sure the water covers the *entire* surface of the dirt in the container. Keep filling up the bucket and using 1/2 the water to water your plants for an ADDITIONAL 3 weeks after the first dose. The eggs hatch every 4-7 days from what I understand...and the extended usage will kill/end the cycle. They think the baccillus is food and eat it...and the shit makes em explode er something and that's the end of the story for em! WHAP!!!!
I now keep the dunks in my water all the time. Damn things...they'l, come back time and ime again...especially in new soils/etc.
Additionally, they like it wet...and they like finely grained soils...so the more perlite and the lighter your soil mix is the less they can get a foothold. (won't stop em..but will help)
The yellow sticky traps will get the adults..but you have to use the dunks along with em or they will still lay some eggs before they get stuck to em.
I've seen no evidence of em for a few months now... so i know it's working.
good luck
bt dt