lighting needed for 90g reef. would like a clam and SPS possibly in the future. please help :)

[radioactive2]

Just getting ready to set up my 90G reef tank. I used to be in the hobby, built a new house and trying to break back in. I have heard a 4" DSB is the way to go? approx 1lb per gallon of LR is needed? I will set up a 30G refugium with a skimmer? Now comes the lighting question, How many WPG do I need for the reef? I really would like some soft corals and a clam if possible. This is what i currently have on the 90G for lighting:
2-175w - MH
2- 48" VHO - do not have the bulbs yet. Not sure of watts for the VHOs
what is the correct way to add WPG?
Sorry for the multiple questions, just trying to get everything figured out.
thank you

 

[deejeff442]

i had a 90 reef with 2 175 watt metal halides and you can keep any coral in it.watts per gallon or 1 inch of fish per 5 gallons is an out dated rule.personally i only like one inch of sand in my tanks.