there are a few products out there. yellow sticky traps are your friend. i always have a few hanging around just in case. there are a few bug sprays made for garden type bugs like gnats that won't hurt the plant. if it's bad, i have some sticky little stick type things that you put right in the soil. little buggers walk right up to it and get stuck. you can also put some sand on top of your soil if you're using soil. there are threads about it.
just do a google search or go to a hydro store. they will have what you need. there are also some doityourselfers who do other things. if it gets really bad, burn the place down and start over!
put a good 2 inches of white sand around your plant and it will not only reflect light but will stop bugs from getting out of your soil and into your growroom. as for what you can do now neem oil is your best bet if they are a real problem. allway use the sand method tho and you wont have this problem again
I battled them for almost 4 months. I am happy to report that they are GONE. Thank god. I used Azamax, flytape, yellow sticky tape, no pest strips and GoGnats.
Fucking bastards. And then a few weeks later I got slammed with Spidermites!! Good luck man.
I have no idea about get rid of the gnats but im using soilless pot...it was easy for me to leach everyday without cause overwater but i have to look out for rotten root thats it...so last night i was watching some marijuana grows on the youtube, this guy showed us how to get rid of that flying gnats, i dont know if its related to yours but if you re still interested to watch his video heres a link
1. sticky traps
2. coffee in cups
3. take top 2 inches of soil out of pot and discard
4. after taking out the top layer of soil, spray layer of perithium on the top soil
5. cover soil with a layer of sterlized sand( heat sand in oven at 300 degree to sterilize for 30 minutes)