I set up a new 25 gallon tank and have been having problems with fish dying. First I bought 3 Emperor Tetras and a rock shrimp. With in the first 24 hours one of the tetras colors had faded it started having trouble swimming and died. Keept a watch on the others and they seemed fine. 3-4 days later I went to diffrent store and bought 3 Kuhli Loachs and 2 Borneo suckers all were doing great. 3 days ago I another of the tetras died of the same thing so I brought them back ( the store where I bought them seems to know nothing of fish keeping when I asked them about this). and this morning my Kuhli Loach was dead but didn't seem to desplay and of the semptoms my tetras had. Any help? P.S. my Beta is in a diffrent tank and doing great.