Metal Halide Questions VS. T5

[lastlight]

I think the 2x150w would be fine.

A single 250 is ok but you'll find the stuff right under it will do far better than the rest (sps) and then the stuff on the edges is going to get less and less light. That's what I found with one light (and what I'm finding looking at my tank front-to-back as the stuff up top grows bigger.