Review on Lee's Pet Products Undergravel Fishbowl Filter, 2-Gallon - ALE13202 by Sandy Martin

I have not yet installed or used this filter but have ordered 1 and 2 gallon filters to see the difference. 1 gallon equals 4 inches in diameter. 2 gallons are 5.25 inches in diameter. The actual filter size is the same on both, leading me to believe there is no difference between them? The hose is 2 gallons longer. and the base is wider, but other than that it's exactly the same as a girl's. The wider base is of no use either, since it is only made of plastic.