Sump with flies

[LauHau]

My 3ft sump sometimes got this flies, they are not mosquitoes, how you guys get rid or prevent them ??

[stormhawk]

Describe the fly if you can. If they are small and grey, and look like the flies you'd see in the toilet, those are midges. If not, they are probably some other fly that is feeding on the stuff that settles in your sump's prefilter, or just trying to lay eggs in the water. To prevent them, just get fine netting and cover your sump, or DIY your own cover out of acrylic.

[LauHau]

tks you for the suggestion, I had put some airsstones, and the flies are gone laiow, tks alot