Hi bigcity51, I'm also from Wisconsin and am interested in energy efficiency. I buy energy efficient appliances, so I started thinking -- how can fish tanks be more energy efficient? (Especially after I saw An Inconvenient Truth -- geez, how do I reduce my CO2 emissions?!)
I havent' really found any answers, and don't know where to look for them.
I would guess that bigger tanks are more efficient (hence time for me to upgrade!!) And using the right size equipment for the tanks should avoid overuse of heaters and air pumps. Also, keep lights on a timer.
I know fluorescent lights are more energy efficient, but are supposed to be replaced like every 6 months -- and I heard they aren't supposed to go in the normal trash (is it mercury vapor in the tube? not sure), but I've never heard exactly what should be done with them.
If I find some better answers, I'll post 'em.