Who Gives A Fish Forums

I'm setting up a 20-gallon high tank and need advice on heaters. What's the best wattage for stable temps? Room stays around 68F, but I want to avoid fluctuations.

For a 20-high, I'd go with a 100W heater. It's enough to handle the volume without overheating. Make sure it's adjustable, tho. Cheap preset ones can be sketchy.

Agree with Finley_8. I've used the Eheim Jager 100W in my 20-high for years. Reliable and keeps temps within 1 degree. Just avoid the no-name brands.

How often do you check the temp? I've heard heaters can fail and cook the tank. Is that common?

badger wrote: ↑Sun Jun 08, 2025 3:57 am Agree with Finley_8. I've used the Eheim Jager 100W in my 20-high for years. Reliable and keeps temps within 1 degree. Just avoid the no-name brands.

Yep, Eheim's solid. I'd also grab a cheap digital thermometer as backup. Peace of mind, ya know?

If your room's chilly, consider a 150W. My place dips to 65F in winter, and the 100W struggled. Just keep an eye on it.

Thanks, everyone. I'll check out the Eheim and maybe grab a thermometer too. Appreciate the help.

I've had good luck with the Aqueon Pro. It's got a shatterproof coating, which is nice if you're clumsy like me.

Heaters scare me. Lost a betta once when one stuck on. Now I use two smaller ones instead of one big one.

Dual heaters are a vibe. Redundancy's key if you're paranoid. Just don't go overboard with wattage.