I think I need to get some IAL. Seems that my purple boy is getting stressed from seeing his reflection and his tail is starting to look ugly and another boy of mine seems to have fin rot. =(
I would try salt too, plus extra clean water.
Works like a charm for tail problems.
I've been doing salt + 100% water changes every other day for almost two months on my blue boy but he hasn't gotten better. He's actually getting worse it seems because yesterday his tail had a couple of long bits and today they are gone and the tail is shorter.