My BP is getting quite large now. He is 4 ft. Prolly almost 2 years old. I am moving him up to a 65 gallon domed front aquarium. The only heat source he has now is a 100 watt ceramic heat emitter in a 20 gallon aquarium. The temp gauges only read 82 hot side and 70-75 cool side. What would be good for heating the 65 gallon tank? Also where can I get what you suggest?