This is one of John's last original Iron Removal Systems. The earlier Iron Systems were made using a galvanized tank with a manual backwash valve constructed from plumbing and gate valves. John McLean would install the system and come back every 6 months to backwash the filter. The later systems, like this one shown, had a 519 automatic backwash control made by Erie Water Treatment. The control valve was very problematic with iron clogging causing a few minor treatment failures. Automatic backwashing was an upgrade to the previous system and required less frequent service.