Heater Question

Vinh · Nov 13, 2015

I have a 50w submersible heater in a 10 gallon and with the cooler weather coming it barely can keep my tank to the desired temperature (78 degrees). The heater is on all the time just to keep up. Before it barely held 76 degrees until I moved the heater closer to the powerhead.

Is it better to have a more powerful heater that can maintain higher temps more easily but continuously flicker on and off or a heater that is always on? I've read submersible heaters break down quicker if they are constantly switching on/off.

Jimmyb819 · Nov 13, 2015

The fact that it's always on means that you are never reaching set temperature. In my opinion this can only lead to temperature swings which is something most of us try to avoid. A heater that is turning on and off is cycling around the setpoint and keeping your tank at a stable temperature.

That being said, an oversized heater that fails in the on position can cook your tank. If you don't have it on a controller which is recommended then you need to properly size it based on tank size, desired temp and ambient temp. There are calculators online that can help with this.

redfishbluefish · Nov 13, 2015

I'm assuming you don't have a controller. No big deal. But I would consider purchasing a temperature controller (like a Ranco) just for the heaters. I'd suggest two 50 watt heaters controller by the controller. Regardless of the brand, heaters will fail, and the dangerous fail is always ON. The controller will protect you from this failure.