I just got a SWR 9500 pump in the mail from global aquarium. WOW...it is a great pump, silent and pushes alot of water. My question is how much water is it pushing (gph) it says 90liters. Aren't there 4 liters to a gallon? if so that isn't correct. The 6500 puts our 947gph. And this is suppose to put out more than that. Anywho, this is a great external powerhead...just thought I would let you all know.