Looks like alot of the members here are new to this hobby like me but also unlike me that I can go back to the old school style of reefing by following my mom's foot step. We have undergravel systems in our saltwater tanks for more than 25 years. There were no home reef controllers, pinpoint testors and skimmers when our first home saltwater tank was setup. BTW, it's older than me.
Scarf, I have seen Wingo's saltwater UG systems, his are not normal UG-they are modified Jaubert systems. The flow is used to flush the system. During regular days the pumps are not on, so it falls back to the Jaubert method and specification of a plenum space. Or, plainly a sand bed with plenum space.