Hi, my betta, Jim is feeling sick. He has what seems to be a lump on his back near his tail fin which looks like it's turning into an open wound. The water in the tank tends to be acidic, I keep an eye on this, change his water about once a week, and use stuff to decrease the acidity when needed. Jim lives with some neons and guppies, none of them seem to be affected. Jim spends most of his days lying on the bottom recently and his colour is less brilliant than normal.
Please help, we don't want to lose Jim.
Thanks, Annagh
