[pogodzib]

A larger return area help give your sump more room for error if your power went out or you sump starts to run dry through lake of top offs or a failure of your ATO system. Having a larger refugium area give you more space for your macroalgae to grow. I prefer having a small return area and to maximize my refugium area. IMO, one should maximize the return area if you have a reliable ATO system and to have your return area and refugium areas closer to the same size if you do manual top offs.