OK, you're really taxing my rather anemic math skills here 8O . My guess is that a 3x250 would do it for the smaller tank, but not the larger one. A MH
is good for about 4 square feet. Your smaller tank has a surface area of about 12.5 so three bulbs should give you pretty good coverage there. However, the larger tank has a surface area of about 19.6...I'm thinking 4 bulbs or possibly even 5 to get really good coverage there. Of course, depending on what you have in the way of corals, you may want some areas with lower light levels. The VHO
actinics should work well. You could set them up in a fan pattern or you could use different length tubes and run them parallel with the front glass. Well, as parallel as you can be with a curved front glass anyway
. The larger tank should be about 7' straight across the front. You could step back a little and run a 6' tube...step back a bit further with a 5' tube, then a 4', then a 3' or a pair of 2' tubes. A couple of Icecap 430's should handle this arrangement well.
If you like a blueish tint, you might just go with 20k MH
's and not bother with the actinics at all. If you did that, you could dispense with a canopy and just use pendants. I think that would look awesome...open top with pendants hung from the ceiling. We're all going to be green with envy when you get these tanks set up