Iron Filters

 Oxidation - Filtration Iron Filters 

This class of filters removes large amounts of iron by first oxidizing it, causing it to come out of the dissolved state, and then filtering it out of solution, capturing it in the filter bed. The accumulated iron is periodically, automatically flushed out of the filter.

Unlike water softeners, these types of filters are designed to allow iron to oxidize in the filter bed. They are equipped with the proper type of medium to handle the precipitated iron and have strong enough backwash flow rates to expel the accumulated iron during the cleanout cycle.

There are several types of filters in this class. These include greensand filters, chlorination-filtration filters, ozone filters and air oxidation filters (known as Chemical Free Iron Filters). Although they each employ different substances as their oxidizers and medium they all work on the same "oxidation - filtration principle", which is, plainly put, "get the iron to rust, then filter it out."

These types of filters should be used when water softening is deemed not to be appropriate for the situation. High levels of iron, manganese, sulfur gas (H2S), high dissolved oxygen or high pH would suggest the use of an iron filter over a water softener for iron removal.