My 12 year old brother brought me Cheezle as a gift for Christmas last year. I have been looking after him to the best of my ability, but he appears to have some concerning deterioration of his fins.
Cheezle lives in a 20L filtered and heated tank with no buddies. I just turned on his heater today as winter is coming and his water is cooling down. He is fed bloodworms and betta fish food every day and appears to be happy.
Cheezle had some balloon mollies introduced into his tank in late December. The mollies nipped at Cheezle's tail, so I removed them and returned them to the pet store the next day. The mollies would have spent at most an hour in Cheezle's tank before being removed for acting like assholes.
Since then, Cheezle's fins have begin to turn white / silvery. He still seems happy and enjoys doing fishy things in lieu of his tail. I have tried to treat his tail with BettaFix, but it doesn't appear to have helped. Nitrates, Nitrites and ammonia all test 0, and pH has remained stable since getting the little dude.
I changed his water completely today and cleaned the tank before introducing him back in. The little guy seems happy, but I just want to take care of his tail before it gets any worse.
Here are some pictures of Cheezle from Feb this year to today. http://imgur.com/a/5Vu9Q
Does he have fin rot? Should I make sure his tank is squeaky clean with water 25% changes twice a week?
Any insight on how to fix this would be much appreciated!