Correct heater watts??

The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.


Aquarium Advice Addict
Aug 2, 2003
philadelphia. PA.
I have a 30 gallon FOWLR tank. Room temp never goes below 73 F. (even in the cold Philadelphia winters) What is the "watts per gallon ratio"? :?
Thanks for any help
I think its something like 4 watts per gallon....i have 2 150 watt heaters in my tank (in case 1 breaks)....i ran just onre for about a month and my temp stayed at a constant 80 ish degrees.....i have a 30 gal also....HTH!!
MT79, Welcome to
Alot of the times it will depend on the heater. From what i have seen heaters are varied in watts and gallon ratio. Check the heater instructions and sides of packages to determine what heater will work for you. As you look around you will notice different ranges of wattage for different heaters HTH
Thanks for the welcome gooyferret, and thank you both- two11devan, gooyferret, for the help, I appreciate it :wink:
Five watts per gallon is the old rule of thumb, but heaters do vary as has been mentioned. Don't use the degree setting on the heater to set your temp. Pick a thermometer from the LFS for this task. Heaters are known to be off a few degrees from what their dial setting says. When you pick a thermometer, pick one that shows the same reading as the majority hanging on the hook in the LFS.
Top Bottom