For submersible heaters, why is it suggested that it be placed horizontally at the bottom of the tank?
Having it at the bottom would make sense during water changes when your tank level drops and you don't leave your heater exposed to the air (which can lead to premature failure).
But why horizontal versus vertical? Is it the same reason why you would place a long air stone horizontal to get better air-water contact for better circulation?
I get great water circulation at the front of my tank because of where the HOB
filter is set up. But that would look silly.
Another place that gets good circulation is at the back of the tank near the filter intake. I don't suppose it would be a problem mounting it vertically the filter intake. Any thoughts on this?