Do I Need a Water Softener, an Iron Filter, or Both?

People who have too much iron in their water may be familiar with issues including metallic-smelling water, reddish-colored water, and rust-colored stains around drains and in appliances. While excessive iron isn’t a threat to health, it can create expensive and unsightly problems around the home if not filtered.

Types of iron that can be found in water

There are three types of iron that can contaminate water supplies: ferrous (or clear water iron), ferric (or red water iron) and iron bacteria. Here is a breakdown of what these types of iron look like in your water:

Ferrous iron: This type of iron is called clear water iron because that’s how it looks in your water: totally clear. That’s because it’s soluble, or dissolved, in water. Even though ferrous iron is clear in water, it will leave reddish stains behind after it has oxidized (reacted with oxygen or chlorine). This type of iron is difficult to remove without being converted to ferric iron, but water softeners are capable of removing low to moderate levels.

Ferric iron: Also called red water iron or insoluble iron, this type of iron is created when ferrous iron is exposed to oxygen or chlorine. It is easy to spot ferric iron water because of its reddish-brown color out of the tap which indicates that the ferrous iron has oxidized. Ferric iron can typically only be reduced by an iron filtration system.

Iron bacteria: While not as common as the two types above, this contaminant is a bacteria that has fed on iron creating a sludgy, stringy rust-colored slime that can do serious damage to pipes and drains by clogging them. The presence of bacteria can also indicate potential health problems with the water. It’s notoriously difficult to remove this type of iron buildup, so testing for it in your water supply is crucial if you notice a slimy material anywhere in your home plumbing. If you have this contaminant you will need to disinfect first to kill the bacteria in addition to iron filtration.

Homes with well water are most susceptible to having iron in their water supplies, but municipal water supplies can have trace amounts that you can detect through the presence of rusty stains left behind after water has evaporated. Treating iron contamination is a unique problem because of the different types of iron, and you’ll need to know which systems will help reduce the type you are dealing with. Both water softeners and iron filtration systems are capable of reducing iron, but there are a few important things to know before deciding between the two. If you’re wondering whether you need an iron filtration system or water softener for iron reduction, you’ll want to continue reading on.

The importance of testing your water

Before you make a decision on which system is right for your home’s water, it is critical to work with a trusted water treatment professional to test your water supply. Knowing the type and amount of iron in your water—as well as any other water problems—will help you understand which water treatment solution is appropriate for iron reduction in your home.

If you test your water and it comes back with more than 0.3 PPM (parts per million) of iron (red water or clear water), you’ll likely see iron staining in your home and want to consider water treatment options for iron reduction. The only effective way to reduce high levels of red water/ferric iron is through an iron filtration system. Most water softeners can reduce low to moderate levels of clear water/ferrous iron, but they are incapable of effectively reducing ferric iron.

An iron filter system is also not the right choice for non-potable water or with water supplies that have bacteria or acidic water. This is why it’s so important to work with a certified lab or trusted professional to analyze your water and find the solution that’s right for you.

How iron filters work

Iron filters are point-of-entry systems, which means they are connected to the main water line right where the water enters your home and filter all of the water before it can make contact with your home’s fixtures and appliances. Iron filter systems contain a media bed filled with an oxidizing agent that converts any clear water iron into red water iron upon contact. The media will then capture the oxidized red water iron so that it won’t pass through the system and into your home.

Iron filters can also reduce low-to-moderate levels of hydrogen sulfide, which is identifiable with its egg-like smell. 

Iron filters are the most effective system for reducing high levels of iron in water—but they don’t catch 100% of iron. Thus, you may want to consider adding a water softener for a total iron solution.

Pairing a water softener with an iron filter

In addition to hard water minerals, a water softener will also reduce low to moderate levels of clear water iron.

When paired with an iron filter system, a water softener can reduce any remaining clear water iron that may have made it through the filter. Because about 99% of the iron will have been removed by the iron filter, the rest of the clear water iron that makes it to the water softener will not strain the system.

What else you need to know about iron filtration systems

Iron filtration systems are a big investment, so it’s important to take proper care of them. Iron filtration systems need to be replenished with potassium permanganate on a regular basis. This will help regenerate the system so the media bed can continue to convert clear water iron to red water iron.

Unlike a water softener that regenerates based on your needs, an iron filter will need to be manually programmed to regenerate on a set schedule. The owners’ manual that comes with your system will let you know how often the system needs to regenerate based on your iron levels and the number of people in your household. It’s also important to wear protective gear when handling potassium permanganate and reference the correct Material Safety Data Sheet beforehand.

All the home water resources you need, all in one place.

If an iron filter isn’t the right solution for you, and you’re curious about other home water treatment systems, visit the Home Water Resource Center. You can find valuable information for everything related to water softening and filtration and feel confident in picking the system that’s right for your home.