Anyone an expert on bettas? My fish has been pretty lethargic the last couple days, laying on the bottom of the tank. Every few minutes he'll dart around the tank, but it's very frantic-like, and he's kind of curled when he does it. He definitely doesn't seem normal. Suggestions? EDIT: He's in a 2.5 gallon tank, no tankmates. No filter. He gets a 50% water change every week or so, and a 100% change every two weeks. I use filtered (Brita) water with a water conditioner.