The most effective method for iron removal is to first have a water sample tested for the type of iron present. There are three basic levels of iron contamination in a well. "Clear water" iron or ferrous iron is water that is clear when originally placed in a container. After a short period of time the water then turns red or brown in color. "Red water" iron or ferric iron is water that is brown or red in color as soon as it exits a water faucet or tap. The last is a "bacterial" iron water and may appear clear upon drawing from the faucet. This type of iron mixes with other acids in the water and then can grow bacteria. In order to perform the correct treatment, the amount of iron present must be tested to afford the best method.
Iron bacteria, which is the most prevalent form of iron present in a water well, is treated by adding up to one gallon of common household bleach to the well itself. Connect a garden hose to an outdoor spigot and insert the other end of the hose into the well casing. Allow the water to flush through the system for at least a half hour. Shut off the spigot and let the water sit in the plumbing pipes for 24 hours. This action will kill off all forms of the bacteria. Flush all plumbing pipes until the bleach smell has dissipated.
Install a dual filter assembly in the plumbing pipe system. The first filter will contain an inexpensive paper filter that will remove the coagulated iron particles formed by the addition of the bleach. The second filter will house the carbon activated filter. The carbon filter will remove finer particles of the iron and aid in eliminating any residue taste or smell of the bleach. In most cases, the well may have to be regularly treated with a small amount of bleach on a weekly basis. Generally, the addition of 3 ounces per week will keep the iron bacteria in check. The filters will need to be changed whenever they become clogged with the coagulated iron particles.
Red-water iron and clear-water iron can also be removed by a slight addition of household bleach as described above. In most cases, though, the filter system will become clogged from the iron particles. Install a greensand filter prior to the water entering the carbon filter. The greensand filter will aid in capturing the iron particles and will have to be back flushed on a periodic basis. In all cases of iron water, a carbon filter will not remove iron on its own. The filter will require either pretreatment of the water or the installation of a primary filter system, such as greensand, to remove the majority of the particles. With no primary filter system installed before the carbon filter, it will quickly become clogged and replacing the filter cartridge can become expensive.