I have a 55 gal tank with 2 bala's and 4 barbs and cycled the tank for about 3 months prior to getting these the same day, and have had the group almost a month. At first, all was great with all of them. I noticed that the bala's color periodically gets lighter, this happened to them as soon as I had them at home. One of my bala's color is so light, it looks like he is losing his color. For a while now, the fish have been hanging around nose down, tail up. This goes for them all. It started with just the bala's but the barbs are doing it as well. I see the barbs chase eachother periodically. So I took a water sample to the store, 2 weeks ago, after my 40% water change when they first started the nose dive float. The water was good. The store rep had no information about the way they hang around. I thought maybe it would pass, but they are still doing it. I can see just at the tip of the light bala's dorsal fin seems to be missing. I do not see any other issues with the other fins, the other fishes fins but the other bala has the same thing. Where do I start? I have searched all over the net and have not found anything about the way they hang around. I have wondered if maybe there was too much agitation with my filtration system, but they don't stay on the side that does not have the filter and they swim around the whole tank. They are eating everyday just fine also, I forgot to mention that. Any advice would be greatly appreciated!