What I do to take care of the gnats is let the plants dry out a little more between watering, put out lots of yellow sticky traps, and throw potato slices on top of the soil/media.
Throw 3 potato slices, sliced 1/4 inch thick into each pot. Wait two days, then go around and pick out all of the slices and dispose of them quickly.
If they are fungus gnats, when you grab the slice on the underneath side you will see little larvae all over it. They love the starch?.
Traps, potato and less watering is pretty effective.
If you don't want to spend a ton of money on the yellow sticky traps buy a stack of yellow construction papar and a tub of tanglefoot. make your own.
I bet they are not fungus gnats, but winged aphids. I think the aphids are going to give you a little more trouble than you are expecting.