Bio-load plus lightning question

[lar]

Currently I have 3 fish that are 6 inches long, 1 fish 4 inch and two 2inch fish.
My tank is 8ft by two by two 240 Gal. What would you estimate I could add to the tank. I have 150lbs plus of live rock.
2nd question, I can not get macro algae going in this tank. especally on the substrate. My lights are 175 watt Halide and one stripe of VHO single bulb through the length. Is the lightning to slight? I position the macro directly under but 2 feet deep.

 

[mr . salty]

First off you have plenty of room for a few more fish. Just add tem one or two evry three weeks. And the lighting does sound a little low on watts. In a good reef tank you will need to have at least 4 watts per gallon. If you were to add two more MH's to your tank,it would kick @$$.