I don't know whats wrong with my neon tetras. They still have great color but are letting them selfs be attached to the filter. I turned off the filters and put sponge around the intake. Theres no sign of illness except that they were sticking to the filter intake and turned them one again. 3 dead, 1 almost dead, 2 swimming around with slightly tattered fins. When I test the water everything is in range. I put in an PimaFix and MelaFix.