I have 3 aquariums. a 55 gallon with a penguin bio-wheel 350, a 20 gallon with a penguin bio-wheel 200, and a 10 gallon with a penguin bio-wheel 150. I kno that the 20 gallon and the 10 gallon have plenty of filtration but I'm not sure about the 55g. how many times should a tank cycle through in an hour??? as of now my 55 gallon is cycling through 6.4 times per hour. is this enough??? the tank does not surrently have any fish in it but it will eventually be stocked to maximum capacity.