I have one of the mini heaters in my 5 gallon that keeps it right around 80 degrees. When I set up Cosmos old tank 1 gallon for Captain I used the same kind of heater, but since the tank is smaller its raising the water temp to almost 84 degrees! Is this too hot for a Betta? It is the smallest heater I can find and without it the tank stays at like 76.
So my question is should I leave the heater in and keep the tank at 84? or take it out and let the tank go down to 76?