i was told i need to use a 60" name brand fixture on my 220 gal reef tank as opposed to using two 36" ebay fixtures. i would replace the grow light bulbs with ati bulbs on the 36" fixtures. his reasoning was the 80 watt 60" bulbs would penetrate the water column better. 4x80 watt 60" bulbs = 320 watts. 8 x 39 watts 36" bulbs =312 watts. the wattage is virtually the same. am i missing something?