I recently purchased this heater for my betta fish, and my fish seems very irritable in the water. I checked the temperature, and it's not too hot, my thermometer I bought isn't seeming to work (it's the kind you stick on the outside of it) and i'm just worried that i'm frying him, even though it's just warm. He's swimming around flared and I haven't seen him take a break yet.
I don't want to take out the heater because he needs the heat, should I just let him get adjusted? Or What?
It's already been a good 15+ hours he's been in there. What's going on?