Have you looked into pool / hot tub heaters?
You can heat it in great many ways and all in all they will cost about the same in electricity charges. The only real and doable savings I think lie in insulation.
How have you protected the outlets where the pumps draw in the water from sucking up a fish, dead or alive against the opening? The pull is very strong. A bottom drain grate / strainer could do it but not a flat one but a dome one.
Also, your pumps don't need to lift the water 6' in the air, as you stated before but only the difference between the water height in your tank and the inlets on the wet-dry filters. But I am sure you know it.
You can heat it in great many ways and all in all they will cost about the same in electricity charges. The only real and doable savings I think lie in insulation.
How have you protected the outlets where the pumps draw in the water from sucking up a fish, dead or alive against the opening? The pull is very strong. A bottom drain grate / strainer could do it but not a flat one but a dome one.
Also, your pumps don't need to lift the water 6' in the air, as you stated before but only the difference between the water height in your tank and the inlets on the wet-dry filters. But I am sure you know it.

