Well i recently divided my 10 gallon tank up and the two fish in it were doing great. IT is heated to 78 and hasn't nudged from that temperature, i have a thermometer in both sides. Anyway. I did a water change on Saturday replacing it with water that had been standing in a 2.5 gallon for 2 days and had water treatment added, this is how ive been doing my fish water for years and it just gives it time to settle. Ever since then ive noticed that both of their fins seems curled up, stiff and "clamped" Im not sure what this means? Possibly disease outbreak? they are both super active like always, and eating very well again, as always. All my water para's are fine (done with liquid test kit) so im just wondering what it could be? will their true beauty ever return?