I currently have a 75 gallon reef tank. My metal Hallides are coming in about a week and a half (2 X 250). I plan on up grading tanks in about about 2 years (what I say to my wife). May be in a year or so (more realistic time). I was thinking about getting something 48 inches so I can us the same lights. But I wanted to hear what people thought of the 120 and 150 48in tanks. I ve heard wider is better. Is it possible to go a foot bigger (60 in) and using the same lights 48 " (That would leave a 6 inch space on both sides). The 48 " halides will be mounted to the ceiling. Can this be done with a 6 foot tank or is this asking for trouble. Let me know what you think. And yes i know , the smart thing to do would be to wait on the halides till I upgrade the tank but like most I CANT WAIT. Thank you all in advance.