I currently have a VERY heavily stocked 200 DD tank with a 125Gal Basement refugium. Obviously with having a large refugium and GFO, Carbon, Bio Pellets and LOTS of macro algae growth I have not had any large issues with NO4 or PO3. I am currently using the typical 2 Part BRS dosing with a DOS/DDR. That is working well and has for 4 or 5 years. Now to the question though, I am considering the Triton method now and updating my Apex from the Classic Gold to the new controller and getting on board with all the new Apex Ca/Alk/MG tester coming. Thanks to a small group setting chat with Tom Dachille of Neptune at my local LFS last night (Ocean Rift Aquatics) I am now almost 100% on board with all of this. Here is my question that I should have asked last night. Since my sump is a basement one and I have approx 25' of head pressure (currently running a Pan World 200PS) it is nearly impossible to get the desired 10x per hour flow through the sump/refugium and Display Tank. If I was to guess I am probably at 5 to 6 times. (My first purchase will be to get the FMK so I can get a better idea of the true flow.) My question is this, can I get away with 5 or 6X through the sump back up to the DT or can I simply setup a DC high volume pump to re-circulate water from the last chamber in the sump back to the first chamber to effectively get to 10X through the refugium even though I would still only be getting 5X back through the display tank?