i am considering buying two 36" t5 fixtures off of ebay and replacing the grow bulbs with ati bulbs. i was told that i need to use a 60" fixture on my 220 gal reef tank( no one makes a 72"?) because the 80 watt bulbs will produce more light. if you do the math the wattage is virtually the same. 4x80watt (72" fixture) or 8x39watt( 2 - 36" fixtures). im my world wattage is wattage or am i missing something. im going this route because of the cost difference from ebay or a reef warehouse.is there a difference
