The three most commonly seen flying pests indoors are fungus gnats, whiteflies, and thrips. All of them have a life stage in the soil. The last 2 munch on leaves and leave pale patches.
I am most familiar with thrips because I have had problems with them. They lay eggs in the soil and tiny larvae hatch out and start climbing up the plants to munch the leaves. The larvae are blondish and look like a splinter of wood, if you can picture that.

All 3 pests can be caught on yellow sticky traps. Peel the backing off and put the traps right at the soil surface.

Pyrethrin and neem are both good controls for these pests.

Be very careful using any chemicals around your buds. My advice is to only use sprays up to the 4th week of flowering, and after that just stick with the sticky traps to keep the numbers down.