Been using NSW for 20+ yrs here in Miami. I would say at least 50% of reef aquarist use It down here. Same thing mentioned, several trucks pick up at the inlet, incoming to high tide, and deliver to LFS and private aquariums. I spend a lot of time on my boat and most of the time I get water right over the reef 6 miles+ out. The parameters of the water are perfect with no nitrates, phosphate,or nutrient problem. I will say though, it is a planktonic soup, and if that's what you want for your tank, take the good and the bad that may be. I haven't had any problems ever with parasites or unwanted pest. I collect through a course sponge that keeps larger particles out.The only other thing I do, is dilute it down just a bit with RO/DI, salinity sometimes around 1.027.