He never has had rounded fins. He is in a 5 gal cycled planted tank. I test the water twice a week, and do a 50-60% water change every Sunday. Numbers are consistent at ammonia 0, nitrite 0, nitrate 5-10. There are no other fish in there to nip fins. I feed him one pellet at a time, so no wasted food. Even when I feed bloodworms he eats one at a time off tweezers. He eats thawed brine shrimp from a little syringe, so no waste there either. Water is crystal clear. Plants are growing well. There are a few snails in there, that I take out whenever I see them, but it is an ongoing battle.
I rinse the filter regularly, every 3-4 weeks.
Is it possible he has some crowntail genes and this is just the way his fins are?
I do have high PH, at 8.0 I have read ths can affect fins.
And, he is always wiggling himself down under plants. The gravel is rounded. No sharp rocks or anything in the tank.
His fins have grown to three times the length they were when I got him 3-4 months ago.