Given the option of 250 or 400 wt metal halide lighting what would you choose for a 90 gal? What would the pros and cons be of each choice? The retros I'm looking at on e-bay are the same price so that doesn't factor into my choice. I will not be supplimenting with actinics so I was leaning towards the 400 with 20,000k bulbs. Thank you for your help