What size is the main/master breaker? Mine's 100A, which means total power draw at any one time for everything in the house can't exceed 100A. You may need a second line run to the house if my numbers are correct. Here's my method:
6x400W Metal Halides per tank for 6 hours/each = 2400W*6hrs=14,400W/hrs or 14.4kW/hrs per day for metal halides per tank. Multiple by $0.16 to convert to dollars if that's what your electricity costs. I also budgeted for actinic supplementation of 600W total per tank for 10 hours/day.
Then closed loop I figured 150W per closed loop pump for 24 hrs/day. I also figured return pumps, the skimmer based on your figures, and "other."
Ron