Is this the 48" tall 125gal tank? If it's a 48" long tank, I'd go with the same fixture I just got for my 90gal; T5 bulbs put out much more lumens per watt than PC fixtures. You can't beat $175, shipped, for a quality fixture with all the bells and whistles this fixture comes with
http://cgi.ebay.com/48-SOLAR-T5-AQUA...QQcmdZViewItem