I've been reading these forums for the past month but this is my first post. I have 2 bettas each in 10 gallon tanks sitting side by side. Last week I switched the filters from aqueon 10's to sponge filters. I have noticed an improvement in their swimming since I took out the strong hob filters. I think they were too strong for them.
This week I noticed that one of my bettas has torn and frayed fins. Portions of the tail seem to be missing. It does not appear to be fin rot. There were a few plastic plants in there but since I noticed his fins were damaged I removed them, so now only live plants remain. His tank has gravel while my other betta's tank has sand. I was wondering if the gravel could be the cause of his fin damage. If it poses a danger I can switch his tank to sand.
I have begun to do daily 50% water changes and I have raised the temperature to 82F. I was wondering if I should add any salt.