Review on Aquaneat Sponge Filter Aquarium Accessories by Maria Gonzalez

This is a great little filter although like me you don't realize the center tube pops out to increase suction. I'll probably buy a few more when I line up my other small tanks. *Update* After a few months of use: Don't expect to feel or see water being sucked into the filter like some other reviewers did. It works by creating a suction from air bubbles that rise up the center tube instead of from the water pump. But it filters water very well and at the same time saturates it with oxygen. And I don't have to worry about juvenile fish or small shrimp being sucked into this filter.