what is the best heater for a 220 gallon fish tank? and what watt?

Answer 1

For a tank your size I would get two 300watt heaters and place one on each end of the tank. I like submersible heaters best since they are easier to hide.

Answer 2

I use a 300 watt in-line external heater on my 80 gallon and it is easy to install and keep regulated. I could not find one that would fit a tank your size, but you can research them on the internet. You could also research Hydorkable undergravel heating cable as a means of heating.

Good Luck