With just Cherry Shrimp, you don't need or really want a lot of filtration. The good thing about the AquaClear's being mentioned is that they all have a simple throttle feature where you can slow down the water flow to almost a trickle. For cherry shrimp, you want to put either a spong filter over the filter intake or like me, use a fine mesh filter media bag over the intake. Any plant detritus caught by the filter media bag will be eaten by the shrimp. I always have lots of cherry shrimp and shrimplets crawling around on my filter intake eating the plant detritus. If the filter media bag starts to get clogged, I just lift up the filter intake tube (which I do with weekly filter maintenance anyhow), slosh it around a little in the tank so the shrimp get off of the mesh bag and then I rinse the bag good before reinstalling. I like the mesh bag better than a sponge since the sponge can hold more detritus and I also worry about really small shrimplets crawling into the holes of the sponge and not leaving it when I need to clean it. I guess it depends on the pore size of the sponge.