So this past month i haven't been home because of school. My husband has been home taking care of all my critters. On my day off i come home and clean everyone's cage/tank. Last Wednesday i changed Leonard's water. I came home today and half of his dorsal fin is gone! I usually do 50% wc once a week. This week I was late by 5 days.
Tank is 5.5 gal
No tank mates
Haven't tested water parameters.
Also i noticed so green gunk on the black part of the heater.
I did 100% wc added 1 tbsp of aq salt and prime water conditioner. He had a minor case of fin rot previously due to a torn fit (stinkin plastic plants lol) and the aq salt cured it. Will it work again? Or should i add something else.