This pump operates great, even under pressure. I'm running ~18 of head pressure on this pump which includes a restrictive section of 1/2" piping through my chiller. Its feeding a frag tank, refugium, chiller, phosban rxr, ca rxr, delivering ~600gph to the main tank, and I still have a 1/2" pressure blow off valve wide open that sprays right back into the sump. Really heavy, well constructed, pretty quiet, like any Iwaki or Little Giant Ive had. Ive run it dry during a couple of water changes, for just a few mins/seconds, and it makes really concerning noises, so I suggest (as does the manufacturer does) not running it dry at all. But lets face it we all abuse our equipment, and time will tell if it holds up to my punishment. Other than that, I couldnt ask for a better pump!