heater

Does anyone here have a "point of use" electric water heater? This is the type that heats the water as you need it. The one I looked at says it puts out 2.6 gallons of hot water per minute. I am concerned that I will not be able to do water changes with it. I am also very interested in lowering...

I don't use heaters in the fish room but the other tanks do have them. which types of heaters do you use.