Of course. You have have your refugium in your sump rather than your tank, or even a completely seperate refuge like the
CPR hang on the back model.
If you were at the last meeting and looked at
Andy's sump, it had a section for a refugium. Usually you want a lower flow for the refugium than the sump, so if you want a lot of flow for your sump, you will probably need to make a bypass, so the 'fuge sees less flow than the rest of the sump. The
Ecosystem brand refugium is supposed to be able to act as your only sump too, but I find that there isn't enough room to put probes, and heaters, etc.
