im starting my first tank. i got a 29 gallon for the main display, and a 20 gallon for a custom sump. after figuring i did not have the experience to make my own sump i decided to use the 20 gallon as a stand alone refugium, and get a pre-built sump. im also thinking of using the refugium in the sump as a cryptic zone, but i don't know if im moving too fast with that. none of it is set up yet and im still in the process of obtaining equipment. so if any veterans can tell if my plan wont work, and what might be a better course of action, this is a good time.