I have a 30 gallon tank with 4 Mollies Black/siler, 3 Marigold Variatus, 3 Sunburst Platy, 1 snail. It is a fairly new tank about 2 months with fish, but it was set up for an additonal 3 weeks before the fish hit the water.
All the fish and the snail seemed very healthy and active until about 4 days ago, one of my black mollies started hiding in some of the rocks, when he did come out (which only happened when I bumped the rock while cleaning the glass) all of his fins are straight back, his tail fin is closed as tight as possiable as well. He (believe it to male) will not come to the surface to eat nor will he eat when the food falls to him.
All the other fish are very active and eat well, I tested the water and it looks to be just fine and I even brought a smaple of the water to my local pet store to confrim, which they did. I should mention the nitrate level was a little high, but a small amount of water change and condtioning additve corrected that issue.
I am at a loss...I am hoping someone might have some ideas to point me in the right direction.