I've had my betta Lucian for about 2 weeks now and the ends of all of his fins, tail, dorsal and the other one (forgot the name), are a little ripped on the ends and red, or maybe even bloody ish. He's in a 5 gallon tank with 3 african dwarf frogs. I can't imagine them biting him especially since he's bitten them a few times

. None of the plants in his tank could rip his fins, and it is bare bottom. I just don't know what this could be... Also another one of my males, Bowen, his fins are reddening on the along the bottoms. Anyone know what this is?? Thanks