Flys In My Tank

Please help my back filter tank is infested with green flies. I cannot get rid of them. I've tried water change, boiling ornaments and filters, completely new filters and pump and gravel. Cleaning chemicals in to clean tank, cycling the tank every time and still the flys come back. I haven't lost a fish yet but I think they must be getting fed up and stressed at being shifted all the time. I can't get rid of tank as its my little girls and she loves it. Plus I have to Hoover the ceiling everyday as they get out and look terrible. If anyone can help I have photos but they are too large for the forum site to upload.

Cheers. Eggs definitely laid in water. I see them swimming around then sort of crawl out of water when fully grown fly. The incubation period is very quick. The life expectancy of the fly is pretty short so might try contain them and hope they kill themselves off. Thanks for trying.

Thanks Steve. I have taken a photo as clear as I can get. Hopefully it loads up. Appreciate the help.

I am no expert, far from it, and the image isn't too hot.  I have spent a while on google, but I haven't seen anything.  I would suggest that you have a look, you have a good idea what you are looking for.  Start off with an image search for "aquatic flies" and see where it leads.

What fish do you have?  Most fish should relish the aquatic stage of such flies.  Do you overfeed them?  Try cutting back on the food and they might turn to your flies!

I don't think a sort of random medication approach is going to help much.  A much better, although more expensive, option would be a UV steriliser on the filter output.

Cheers for the reply. I have been killing as many as I can. The water at the back is quite calm only movement is from the pump so I might drop in a air stone for a few days as it looks like the larvae seem to stick to the side when they are due to hatch, so if the water is moving they may well not hatch.

In relation to the water changes I'm thinking of doing 25% changes but a little unsure of how often as not to stress my fish, what would you suggest maybe every 3-4 days.

I have also limited the food intake, was also thinking of dropping in a holiday block of food rather than fish feast as this may eliminate a food source for the larvae.

Also to Steve s. cheers for the heads up on the uv steriliser looking into one. The medication was my local fish shop ideai so thought it was good shot. (Probably just trying to make a sale).

Thanks for help will let you know how it is going.

Cheers sue will give that a miss then. Will try the other tips.