Hi guys! For those of you considering the Red Sea Reefer 750 XXL and decide on the Reef Octopus return pump make sure you get the VarioS 8.....NOT the VarioS 6. I let the LFS get my pump because they also brought out my tank etc.....and they got me the S6.....not near enough flow....after I accounted for head height loss of about 4.5 feet it was only putting out 1100 gph or so running the pump at max. The recommended flow for this tank is 1850 gph. So I just installed the S8 and running at max counting for head loss is 2000 gph. It already makes a huge difference! I know....it took me six months to figure it out. LOL! [emoji849][emoji50][emoji45]