Iron contamination is a common problem in well water and municipal water. Though some amount of iron is good for health, beyond a certain level it may be harmful if pathogenic bacteria that grow on iron have entered water. The major problem with iron arises to plumbing fixtures and gives a metallic taste and odor to water. Iron may be insoluble or soluble iron. Dissolved iron is also called as clear iron water which seems clear when it flows through the faucet but turns red or brown if left standing. For this reason it is important to have clear water iron filters. You may not require sediment iron filters or carbon filters for removal of such iron. To remove clear water iron the best media is the water softeners which involve a process of ion exchange.
Clear water iron is common but not hazardous to health. Dissolved iron in water is identified when you pour it into a container or glass and allow it to stand for few minutes. Reddish brown particles appear and may settle down to bottom of container. The most common clear water iron filtration systems use manganese greensand technology which is an ion exchange sand material. The technique involves adsorption of dissolved iron. Iron filters take clear iron and transform it into rust or ferric iron. It also requires chemical regeneration and periodical backwashing. Water softeners also help remove soluble iron by ion exchange.
The manganese greensand that is commonly used in clear water iron filter is the most common chemical oxidant with high capacity for iron removal and moderate backwash requirements. Typically it is made from nodular grains of zeolite mineral glauconite which is coated with manganese oxide. The ion exchange property enables bonding of coating which in turn gives the media a catalytic effect in chemical oxidation reduction process that helps iron removal. The coating needs to be maintained by regeneration with potassium permanganate.
Another media is Birm which is commonly used for filtration. It acts as a catalyst to promote reaction between oxygen and dissolved iron. It does not require regeneration but performs best at pH above 6.8. Similarly pyrolox is a natural ore that oxidizes. It then filters the insoluble iron. Regeneration is not required, thus no chemicals are added. However, a backwash is needed every 25 to 30 gallons per square feet. Typically birm filters are used for removal of dissolved iron but one which does not have the odor problem i.e. hydrogen sulfide present. The manganese greensand filters and pyrolox filters are perfect for removal of iron and manganese with odor.
Various manufacturers have developed clear water iron filters. Depending upon the level of hardness, the level of hydrogen sulfide and pH of water you can choose the best filter. It is very important to carefully choose clear water iron filters, may it be for whole house systems or point of use systems and cartridges. Research of clear water iron filters is necessary and a decision based on analysis of water and type of filter would ensure that you get clean and pure water. It would be fit for drinking as well as reduce substantially the unsightly staining of appliances, fixtures as well as laundry and dishes.