Originally Posted by jcahow
Hydor ETH external heaters work great on Eheim canisters!
I have a dozen of them and have never had a problem.
They remove one more thing out of the tank and you do not have to worry about electricity or your fish breaking them.
A 200W on a 40 gallon breeder is the exact setup I have except I am using an Eheim 2073 Pro 3 canister.
When the heater activates the little red light on the side should light. You should be able to feel the heat in the water pumping back into the tank.
Either the heater is not working or the water flow back into the tank is so low it cannot heat the water.
Not sure what your problem is but many others have praised ETH heaters here as well....................
I've gotten two of them from this guy on eBay and both of them havent heated my tank at all. I even tried cutting the flow down to less then half to see if the water was passing through the heater too quickly. Nothing has worked. What are the chances this guy sent me two broken heaters?
The red light doesnt stay on for long at all, and when it is lit, I dont feel any difference in water temperature. He told me I shouldnt feel a difference from the sprayybar and the tank water because the temp difference is so small....IDK what to make of that whole thing.
I have herd nothing but good thing about these heaters, so I decided to order one from foster and smith on line. It will be here Thursday, so hopefully this one works.::fingers crossed::