I've got a male Betta whose fins keep disappearing - they turn translucent and shorten, then they heal, then they fade and shorten again. He swims just fine, looks otherwise healthy and doesn't seem to be in any pain, but it bothers me to see him like this. I've checked his chemicals over and over but they're all right. He's only got smooth plants in his tank. This has been going on for months. Is this normal? Has anyone else seen this happen? I've tried treating him with BettaFix, but it only brings temporary regrowth. This has me baffled. Would appreciate advice or reassurance.