I'll try to answer all the questions:
There will be between 100-120, 2000- watt MH lights on the main tank at the Steinhart, augmented with natural light. We have a scale model they have been working from, complete with scale representations of PAR values using fiber optics, so they know what light intensities will be where, and where corals will be positioned. The tank currently running at Howard Street is the same depth as the new tank will be, so they have been and will continue to be doing research on light intensity and coral placement. That tank is now using the same 2000 watters that will be on the new tank.
So, a quick calculation of kilowatt hours for 120, 2000 watt MH lights on for 10 hours at $0.12/kwh gives you $288 a day to light the tank!
Not sure how much water we will change or how often, sorry.
I did JUST get my 70 gallon last week, but have to finish other renovations before I can start setting it up- lots of cabinets to build. I think by June it should be up and running!