The trick to using Magnasol is to not PUMP it! I use mechanical stirring then let set overnight. Pump mixing is not the way to go, and has caused lot's of people to not use it. Pump mixing causes shearing of the Magnasol particles and makes it a real pain to filter out. Mechanical mixing will not shear the swollen magnasol particles, and overnight settling, then pumping the bio from the top of the mixing tank removes almost 98% of the Magnasol. As I pump the bio off the top of my settling tank I filter down to 1 micron.
Over 10,000 gallons so far, and NO problems!