Yes bugs are hardly ever good but gnats are among those which are actually *relatively* harmless. But they are bad for seedlings because they eat on the roots, but not so much for older plants.
Gnats are almost ALWAYS a sign from over-watering because they live in wet/humid soil. So when you see them, turn down your watering. (You should always let your soil "dry out" between waterings, even if your plants start to wilt because they are dry, this is not an issue because they recover within an hour or two. I often actually only water once I see plants wilting. MUCH better than overwatering!)
Aside from watering less (which should get rid of gnats), you can also cover the top of your pots with perlite, sand etc. so they can't lay their eggs in there.
Gnats are almost ALWAYS a sign from over-watering because they live in wet/humid soil. So when you see them, turn down your watering. (You should always let your soil "dry out" between waterings, even if your plants start to wilt because they are dry, this is not an issue because they recover within an hour or two. I often actually only water once I see plants wilting. MUCH better than overwatering!)
Aside from watering less (which should get rid of gnats), you can also cover the top of your pots with perlite, sand etc. so they can't lay their eggs in there.