Are you looking at the 4x54w? That will give you just under 4 wpg going by the numbers. You can't make it anymore than that because of any type of reflectors, its a mathematical impossibility. HOWEVER, it's important to note that just because a light fixture produces x amount, this does not mean that your going to get all that light directed into your tank. So the better the reflectors, and the type of bulb do play a factor, and is going to improve the factors of lighting in your tank, but it's not going to raise the WPG.