Well, I had to do some switching around of tanks and I had to move my Crowntail and Veiltail male Bettas from my 20g to a 10g divided. Unfortunately I apparently left a big enough gap for my Crowntail to squeeze over to the Veiltail's side. I was gone for 2 hours while it happened so I have no idea how long they were together. Needless to say I freaked out and immediately separated the Bettas, along with cramming some filter floss to where they cannot get through the gap. They are both understandably tired and wounded from their battle. I estimate they both lost about 1/4 of their total finnage.
My biggest question: Is there anything I can do beyond frequent water changes to keep the water quality perfect? I feel like such a crappy owner, so any help is appreciated.
EDIT: I'm going to feed them some garlic infused food since it should help as a mild antibacterial. Should I grab some natural peat moss at Lowes and put a bit in the filter since it could be helpful?