I just noticed My albino Cory which I have had for about a year has absolutely no top fin, no bottom and no side fins (2 stumps is all that is left). He does have healthy long tail fin and fairly long whiskers. he seems to be eating fine and is quite active and does charge to the top for Air. i checked my levels with API Freshwater master test kit, ph is 7.8, ammonia was .25ppm (normally 0), nitrate and nitrite 0. Temp @ 76. Tank is established 30 gal, change 25% every 2 weeks. 2 weeks ago changed filter carbons, add 1 capful Nitro max at water change & 1 capful fish keeper 1wk later. normally use RO water for change. This has been same routine for 1 year. However last time used tap, before adding to take added stress ease to water then slowly added water. Didn't notice any issues. with exception of long finned tetra(started swimming vertically) nothing else has shown signs of stress. No other fish seems to bully another from what I can tell. both gromies get along surprisingly well. feed every three days flake food every 6 sinking pellets. In between algae wafers. Nothing representing fuzz on any fish or "bald" looking Cory. Search Internet. No luck. Any suggestions.