Recently corrected water softener plumbing (resin could be fouled).
Replenished calcite and corosex.
Replaced MTM media.
Replaced Fleck 7000 valve on MTM tank as the old one continued to leak and I think it was due to gear wear rather than seals/spacers.
Replaced Centaur Carbon.
Surprised to find that carbon seemed fouled after six months of use.
Will investigate carbon valve settings.
Flushed retention tanks and found little if any evidence of precipitated iron.
Water again running clear.