My male betta is acting odd.
I have him in a 2.5 g tank with lighting. He has moderate hiding space.
2 days ago I put new gravel in and did an 100% water change. He seemed fine. This morning I feed him some BettaMin flakes. Now he looks bloated and is floating on his side. At first I thought he had died but when I put my hand on the side of the tank he tried to swim downward but floated up. He did the same thing a few weeks ago but after a day or two it would go down and he could swim again. What am I doing wrong? Is there something I can do?