Yes you are right. 3kw is what I meant. I was thinking of a recommendation of using multiple heaters, like (6) 500 watt heaters instead of one 3kw. The reasoning was if one went out the others would keep operating until the faulty unit was replaced. But thanks for the response. My tank is going to be in my greenhouse. So I figured the snorkel stove would also increase the ambient temp. because the top of the stove and the chimney will give off heat as well. Also my intention is to fire the wood stove to decrease the electric consumption not to completely replace it. Unless of course I lose power, (couple times at least every year.) Last year the outage lasted a week. Then I figured I would need a generator to charge and maintain a twelve volt back up system for aeration and at least partial pump system. Still working out all the possible scenarios to prevent total losses. Thanks again, I appreciate your input.