I have been using this salt for 6 months now and I'm very happy with it. Mixes with no trash settling out of it. I ran out a few months ago and used some HW Marinemix reefer I had lying around. My pH tanked almost a solid point and it's been difficult bringing it back to its original glory. Probably a crappy batch of HW if you ask me.As far as the Fritz RPM, I love the salt. It's locally made, consistently good quality, and it's not going through tons of shipping that increases the risk of exposure to humidity, sunlight, etc. +1