I've had my betta since July, so it's been about 5 months. I haven't had any problems until now. It's pretty cold now and I noticed that the heater I have in the tank isn't working as well, most likely because of how cold it's been and my fish isn't eating. I'm not really sure if I should get a bigger heater or move it out of the back compartment of the tank and actually put it in the main area. I'm iffy on adding another heater since my tank only holds 3 gallons. Another thing that I noticed is we was trapping himself under the piece of wood in his tank, and he never did that before (I'm sure this is how he tore his tail) I'm really don't know what to do, so I would appreciate some advice. Thank you!