Using two heaters at different wattages?

[ticojpunk]

I'd like to use two heaters for redundancy. I'd also like to just use what I've got.

I have a 100w Aqueon Pro (the older blue knob type)
and a newer 150w Aqueon Pro (with the clear knob that lights up red).

Would using these together in a 29g tank be an issue? I'd run them on opposite sides of the tank of course. My main concerns would be too much total wattage, and possibly an uneven heating due to wattage difference.

 

[carsonsgjs]

Feels like overkill to me. I’d just use the 150w which should get the job done on its own.

 

[TClare]

I don't think it would do much harm to use both, the wattage would not be too high as both heaters would switch off when the correct temperature is reached, also from experience, having two different sized heaters is not a problem, I have a 200W and a 75W in my 240l (64 gallon) tank. But I don't really see the point in your smaller tank, as you would presumably still have the 100W spare in case of the other failing. Why use up more tank space?

 

[ticojpunk]

I don't think it would do much harm to use both, the wattage would not be too high as both heaters would switch off when the correct temperature is reached, also from experience, having two different sized heaters is not a problem, I have a 200W and a 75W in my 240l (64 gallon) tank. But I don't really see the point in your smaller tank, as you would presumably still have the 100W spare in case of the other failing. Why use up more tank space?

All fair points. That older Aqueon pro with the blue knob has been my backup heater for years. Recently had a regular Aqueon heater fill up with water suddenly and I was glad to have it on hand so I could quickly get that water-filled heater outta there immediately and have another heater to put in without any stress.

 

[Redshark1]

I'd advise just using one heater as it is less hassle and the seal deteriorates underwater over time. Stick a mini thermometer in the top corner of your tank and check it at feeding times and you'll notice if your heater is amiss (and the fish behaviour should also indicate it). Replace heater if it shows condensation in the glass tube.