Been eyeing that shower system. I think the concept is that you prefill the bottom tub with hot water and then recirculate from there, so the pump is the only thing that gets "fouled". Shouldn't be a problem. One cool extra mod would be to add a valve that allows you to switch from "recirc mode" to to "fresh instant hot water mode" for a nice clean rinse after the dirt and suds phase. I'm designing that exact system. I figure a three gallon 15 minute hot shower is possible that way!I DIT NOT think about that! Hmmm..... I will have to deal with that issue somehow. Thank you for bring it to my attention, thats a damn good point.