The best heater

[ThePearlFish]

What is the best heater for a 20 gal. long tank?

~TPF

[aunt kymmie]

IMHO: Marineland Stealth Visi-Therms are the best. I'd go with 2-½ watts per gallon if the temperature in the room where the tank is won't fluctuate more than 10 degrees. If it will fluctuate more than that, go with 5 watts per gallon. I have two 250 watt heaters on my 100gl, and 25 watt heaters on each of my 6gal tanks.

[Nataku]

Marineland generally does have the more reliable heaters of the various brands I've used so far, they take a beating even in salt water tanks and keep going. Topfin's are good too, but I have found they tend to live a shorter life than the Marineland ones. I've had Topfin's croak after three years, and Marineland heaters that are pushing ten years now and still going. A 20 gallon should probably have a 75-150 watt heater, depending upon how cold the air temp of the room the tank is in is going to be.