More of a lighting question but DIY as well.

[Lance]

I have 3x400W 13000K Geisemann MH and 6x39W T5 actinic and 2x39W T5 10000K on a 24" deep tank. The light is 18" above the water.
The tank had way less light before the new fixture and after acclimating the softies and LPS to the new light they are all doing fine; in fact, most of them are growing faster and have better colour than under the old fixture. Hopefully this helps. Good Luck.