I run an AC 110 and the smaller Emporer 280 on my 75G and 55G pleco tanks. And two Emporer 280's on my 72G discus tank. The AC 110 gives me the fast flowing water at one end while the Emporer has a gentler outflow at the other end for the fish that want to stay in calmer water and not get blown around. Filters at both ends of the longer tanks also do a nice job of circulating the heated water around. I run a 300W heater at both ends of each of those tanks. I stuff some fluval sponges in the Emporer HOB's prior to the cartridge to catch the large particles. I rinse and reuse my cartridges for months and months. Doesn't matter to me that the carbon no longer works, by the time the carbon life is expended, the cartridge becomes an established piece of biological media in that filter. My AC 110's have a very fast outflow, even when set at the lower intake setting. My discus don't like that much flow. On the other hand, my Siamese Algae Eaters sleep in the outflow. They seem to love the fast flow more than any of my other tank inhabitants. The only complaint I have about the AC filters is they need to redesign the intake. I learned the hard way that the intake is no match for little fish like ember tetras. I now have to keep sponge filters on the intakes of all my AC filters, even the smaller ones on my smaller tanks. I never have that problem with the Emporer filters.