I put up a diary
With many different methods. And I swear. It got so bad. All I had to to was push a little soil about. And about 50 little shits that are waiting on their wings.
So, yellow sticky traps..fruit fly traps will get rid of any males.. and then its your job to sort out the soil.
There's num ways to treat it. Have a look.
Cinnamon you use to pour around the traps as its a natural fun they'll go to that. And you trap them or lay out some pest DE around it.
Let you soil dry out. If you have to feed from the bottom up. So just sit your pot in a few 100mls of water. No nutrients. This might cause light green on sides of leafs but it's part in parcel of getting rid of them. Now when your soil is dry by a few inches on top. You'll have inert larva just watering for you to water again. So gently remove the 1st few inches (this is just an extra percausion..
Have a look at my diary. Fungas gnats, fruit flies.
The flyers like to get near the lights or exhaust fan you'll catch a lot with yellow bug traps..
Good luck