Drain fly problem??

[GrifTheGreat]

Try what David has stated above. Its about the only way to stop them.

[IvoryReptiles]

You'll also have to clean & replace the substrate & any furnishings.....there may be eggs on any of it and if you don't get rid of those, you will never be rid of the flies.

[dpcsquid]

I would think you could also maybe try luring them out and killing them. In my house when we get fruit flies (I'm guessing that's what drain flies are?) I get out a shallow bowl and fill it with apple cider vinegar and put in a drop of dishwasher detergent. The pungent smell lures them onto the liquid and the soap keeps them there. It makes a stink but it does the trick. Maybe keep a bowl somewhere nearby the tank and see what happens, on top of cleaning the tank?

[GrifTheGreat]

I would think you could also maybe try luring them out and killing them. In my house when we get fruit flies (I'm guessing that's what drain flies are?) I get out a shallow bowl and fill it with apple cider vinegar and put in a drop of dishwasher detergent. The pungent smell lures them onto the liquid and the soap keeps them there. It makes a stink but it does the trick. Maybe keep a bowl somewhere nearby the tank and see what happens, on top of cleaning the tank?

Not quite like regulate fruit flies. Drain Flies are much smaller. Like half the size of a regular fruit fly or less. That's what makes them so hard to get rid of. They can fit through almost any mesh.