I got one for my 55gal, and 2 for my 120.....I use the same stuff that comes with it, along with extra filter foam (white puffy kind) brains dead right now, and a bag of carbon & zeolite @ 1 cup in each filter ....
Rinse them all off every 2 weeks, change the white puff stuff haha, and change out the carbon bag every month.....
My water is cyrstal clear and works great....But then again im almost tripled teh filtration of the tanks....each "rated" at 175gals each....