100 watt heater for a 20G?

[Fish Hunter]

I just wanted to know I have a like new 100 watt heater laying around. Could I use it in my 20G? Or would it be to strong?

[OrionGirl]

I wouldn't, because of the potential for the heater to malfunction and boil the tank. If you're using the tank for quarantine or hospital, where you'll be watching it closely each day for the entire time it's in use, this is fine, but for a display tank, where you might not check the temp daily, it's a potentially lethal problem.

[Sumpin'fishy]

I have been using a 100w heater on my 20 gallon tank for over 4 months now. I generally tend to use the 5w/gal rule. Some people dislike it, but I like being able to keep temps extra stable, and my heater also doesn't have to work as hard or as often.

[brianfl]

Should be perfect.

[kdblove_99]

I think it will be fine.

[Hebdizzle]

Lol i have a 100 watt heater on my 10 gallon. works fine

[ROLLIN]

I also use 100w heaters on 20g's.

[JSchmidt]

A well-functioning 100w heater will be fine in 20 gallon tank. For that matter, so will a 200w heater.

The problem is the potential for disaster should the heater stick in the 'on' position. A malfunctioning 100w heater will quickly turn your tank into fish soup. You can use a large heater on a small tank, but it greatly reduces the time you have to catch a heater going bad.

Want to experiment? Set your heater to its highest setting and see how long it takes for your 20 to reach that point (don't do this with fish in your tank, of course).

HTH,
Jim