[pineapple]

I have the 0.5" model in a tank right beside me in the office and it doesn't make any sound when switching on or off.

Andrew Cribb

 

[pineapple]

The only issue I suspect - but have no evidence of - is that the Hydor ETHs can only raise the aquarium temperature at maxmimum 10 degrees F above the ambient temperature of the room. If you have an aquarium in a basement or garage which gets very cold during the winter, you might consider getting a heavy duty, work-horse, in-tank heater.

Andrew Cribb

 

[pineapple]

Aquaverde is right, I should have said C not F. Apologies. I am very happy with this heater, by the way. Some of my tanks are in frigid locations and the heater does very well.

Andrew Cribb