I think I have the exact tank you have? I went fresh water no plants. The water is very clear here in AZ and the light seems to make it all the way to the bottom 
I'm using two 4' colalife fixtures over lapped in the center. Each fixture has two 65w 10,000K bulbs and it's more than adequate lighting for my needs. Apples to oranges comparison to your SW set up.
I hope some if this info helps. You can always add more lighting if needed.

I'm using two 4' colalife fixtures over lapped in the center. Each fixture has two 65w 10,000K bulbs and it's more than adequate lighting for my needs. Apples to oranges comparison to your SW set up.
I hope some if this info helps. You can always add more lighting if needed.