How much iron will a water softener remove? There are two drastically differing views on this subject. One the one hand, I have heard that water softener resin will remove up to 8 ppm (Parts Per Million or milligrams per Liter – mg/L) of iron, but that was from a softener resin manufacturer. Then on the other hand I have heard that you should not treat any appreciable amount of iron with water softener resin.

The fact is that common cation water softener resin will also remove iron which is prevalent in a vast number of private wells throughout the country. But how much iron will a softener remove before it becomes impractical? Every answer comes back to knowing what – and how much – is in your water.

If you have a hardness problem and a minor amount of ferrous iron in your water, a water softener is the right choice. The ferrous iron should be 3.0ppm or less. There is no mathematical formula we used to come up with this figure, it’s simply what has worked for Water Value Company over the years on local (West Michigan) private wells. If the amount of iron is between 2.0ppm and 3.0ppm, we will usually consider a turbulator which helps to more aggressively loosen the iron from the softener resin beads. Anything over 3.0ppm of ferrous iron should be treated with one of the various filters designed especially for iron treatment.

There are many water treatment companies that offer special “fine mesh” softener resin media which provides more surface area for iron capture, but the inherent problems with fine mesh resin prevent us from making that available online. Water softener resin is not designed to remove iron, but it does so incidentally. If you really have an iron water problem, you should look into an iron filtration system designed specifically for your type of iron. See the different types of iron here.

For most well water applications, a water softener works out just fine. It will handle mild iron and some pretty high hardness levels. But because iron particles adhere to cation softener resin beads so readily, does not mean that a simple brine (salt saturated water) will remove them efficiently. There are softener salts designed for removing iron from resin media. Morton has one called “Red Out”. This helps a great deal in aiding backwash removal of iron by including a mild acid with the salt pellets. And as stated above, a turbulator can help prevent iron buildup on resin beads.

So if your main water problem is iron, either ferrous (clear water iron), ferric (red water iron) or organic (often the cause of tannins), it is best to consider a water treatment system that is designed for those types of iron problems. Here are some water treatment solutions designed specifically for iron in water problems.