Heaters: 200w in a 20g is overkill?

[irishspy]

I suspect it is. For reasons too long to go into, I have a 200w Rena Smartheater as the only available heater for a 20g long tank I'm setting up. Am I right to be concerned that's too much power? I can get a 100W very easily, but, before I do, I want to be sure my suspicions are correct.

Thanks much,

[FinFanatic]

Overkill? Uh, yeah ;)

But I don't think it means you can't use it. I'm not super familiar with heaters, but I'm guessing it would take less time to heat up the tank to whatever setting you set, as opposed to a smaller heater.

Anyone else agree/disagree?

[J double R]

using a higher wattage heater just means that it will take less time to heat, and spend less time on. some people will argue that it might cycle the thermostat too much, but I've used similar wattage heaters in small tanks without any issues in the past.

[irishspy]

Thanks for the opinions. I've just ordered a 100w. I'm more comfortable with something around 5 wpg than a 10 wpg "nuclear power station." ;)

[kanvas]

I don't know it's a isolated problem but when I had a 150W in my 10, what happened is that the temperature was be higher than what I set on the dial. I set mine at about ~72F and the actual temperature reading is closer to 78-79F. When I placed it in a 20 gal, the temperature became much more accurate. In short I don't see any "bad" effect if you do that, just pay attention to the ACTUALLY temperature reading for the first couple days and adjust the heater accordingly.

[mellowvision]

I have a 200w in a 15g and I like it a lot more than having a 50w in there... the 50w would run so much longer, but the 200w just comes on here and there to stabilize the temp. I think running a higher wattage is a good thing myself.

that said, I have a 100w in an identical tank and see no difference in operating temps or times.

[nc0gnet0]

I think the only issue would be if the thrmostat on the heater failed, then you have instant fish soup.

[stevent]

All you need is a 100w in a 20g.