For a Birm or MangOX iron filter to work properly, there must be enough dissolved oxygen present in the water to oxidize iron and manganese particles for filtration. A good way to achieve oxidation without having to install an open atmospheric pressure storage tank and additional booster pump is to aerate the water by passing it through a head of air as it enters the iron filter tank. The air can either be injected with an external air compressor, as in the Maxi-Vent systems, or it can be drawn in during a backwash cycle, as in an Air Charger system.
An air charger is simpler and will require less maintenance than a system with an external compressor, since the whole oxidation process occurs in one tank. Air charger systems function by drawing in air during their backwash cycle and keeping a pocket of air above the filter media to oxidize iron and manganese. The air charger iron filters that we carry come equipped with a Fleck 2510-SXT air injection control head that automatically backwashes the system daily to clean the media and flush out particulate in addition to drawing in air for oxidation.
Maxi-Vent air tanks, on the other hand, function by pumping air into a filter via an external compressor. While an air charger filter will only filter about 7 – 8 ppm of iron and hydrogen sulfide, a Maxi-Vent system can filter from 5 – 20 ppm. And because the Maxi-Vent system has a separate air tank and compressor, one can always be sure that there is a head of air in the filter tank for aeration, without the need to run a backwash cycle every night.
Another method of oxidation would be to use a chlorinator system before your iron filter. We have covered this method in previous blog posts, and we also have more information about oxidation by chlorination on our resources page.