Stradius011

How many watts should the heater be for a 29 gallon aquarium?

atmmachine816

150w, 5 wats per gallon

atm

Stradius011

Okay.

atmmachine816

Best to get two 75w heaters so if one breaks the other one will pick up the slack and your tank won't freeze.

atm

Isabella

I have one 150W heater in my 30 gallon tank, but ATM is right - it is safer to have 2 x 75W heaters. This way, in case one of them breaks, you still have the other one working, which will give you enough time to get a new heater in place of the broken one.