rare disease

Instead of medications, why don't you try frequent large (50%) water changes? If you think water quality is the problem, dumping more stuff in there rarely makes the water better. Big frequent water changes can prevent and cure a lot of stuff.

angel fish can be messy...(especially if big) I think you should do a 25-50% water change every other week

Large water changes don't upset the biofilter unless the pH, temperature, salinity, or nitrate levels are very different, which can shock both fish and bacteria. Check those first, if you are concerned... in tanks with infrequent water changes, this is a good idea. I should have asked what your regular schedule was

The biofilm you don't want to upset is on the surfaces -- gravel, glass, plants, decorations, filter and filter media -- not swimming in the water.

You can test for ammonia, nitrite, phosphate and nitrate, but although nitrate is a good indicator of other things building up, it's hard to measure dissolved organic compounds, proteins, hormones, contaminants from the air, etc. which in high enough levels supress the immune system of fish and make them prone to bacterial and fungal diseases. Carbon will remove a lot of these if it's changed frequently enough.

If you only change 20% every couple weeks, that's really not very much water turnover in your tank at all, so maybe start slow, as your tank water may have become quite different from your tap over time. Change 20% every day or so, then more. Those cloudy spots in the fins really sounds like the tank needs a freshening. I had something that sounded just like that on some neon rainbows and keeping the water very clean cleared it up.

I do 50% water changes on all my tanks every week. A lot of people do.

I agree

Although I can't be sure without seeing the fish - its sounds like your angels have lymphocystis. Bad news: this is caused by a virus and there is no real cure for it. Good news: its not fatal. Fish normally pick it up when they are really stressed out (i.e. in a tank at a wholesaler) and crowded with other fish that carry the disease. The most significant effect of this disease is that it can be disfiguring and unsightly. You can remove the cysts yourself, but without the right tools you could actually cause more damage and stress to the fish. The best thing to do is to make sure your water quality is proper for the type of fish you have. Angels I believe normally like softer, lower pH water etc. You should look into this if you haven't already (check www.fishbase.org). Also look at things like diet and tankmates.

Breakouts of cysts normally occur around episodes of stress and lowered immunity.

I also agree with others that responded regarding water changes and quality.

I think they will get over it in a while

Originally posted by keely
The biofilm you don't want to upset is on the surfaces -- gravel, glass, plants, decorations, filter and filter media -- not swimming in the water.

Click to expand...

Keely, that is the best explanation I have seen yet! Thanks for that, it will come in handy!



I also agree that large water changes, and/or smaller water changes on a more regular basis aren't going to be any harm.

Last week, my nitrAte levels sored, so I did a 50% water change. I tested again, and the NitrAte level was still rather high, so I did another 50% water change... Then I did another 25% one. Finally, after all that, my NitrAtes (and everything else) were back to normal, and the fish/tank are fine.

Good luck!