12 year old iron filter rebedded two years ago. New pump this year to improve pressure/GPM/aeration/backwash. Don't recall the numbers from the water tests but lots of iron. A pail of unfiltered water left overnight looks like I mopped up a slaughterhouse. Water let to sit after filtration stays clear yet get iron stains on the grout. RO pre-filters discolour. Using RO water in my coffeemaker, there is a stained high water mark. My water guy says it can only do so much.
When an in-line micronizer is used oxidized iron precipitates out in the well tank and clogs the lines from well tank up to the precip tank and frequently inside the backwashing valve itself. Mud-balls occur in the precip tank causing precipitants to build up in tank. The ferric iron bleed may be due to pressure loss in the aforementioned areas. These systems need to backwash every day. I would suggest taking out the micronizer and install an air pump to inject air directly to precip tank.
RJ