You guys know he's in a HUGE tank, so space is not an issue. Every now and again, he blows or bites his tail and that seems to grow back fine. But his anal fin and his ventral fins are curling like crazy. At one point one ventral grew into itself in the shape of a C. I put a half dose of betta fix in his tank to help his tail heal and noticed that the ventral uncurled a bit just after and while it's still curling, it's not grown into itself anymore.
So I guess my question is, what causes curling besides water quality? I test my params every week, do weekly small water changes and vacuuming. His parameters are almost always 0,0,5 or 0,0,10. PH is 7.4 to 7.6.