How long does softener media last? When should the auto-backwashing filter media be changed? Not even the manufacturer of the media knows for sure and with very good reason. First, do you know how much water has passed through your 2001 softener? Any idea how much chlorine it has been exposed to? How about your iron filter media? Has your greensand filter been regenerating often enough or not? The fine coating on manganese greensand media can wear off, but after how long? How many regenerations will occur before it needs replacing?

Softener Media: Let’s start with softener media. Specifically, cation softener media used for exchanging chloride ions with calcium ions. While cation softener resin media can also remove iron to an extent, we’ll focus on hardness removal only. How long before this media needs replacing? Softener resin media is basically very small plastic beads which is described as “polystyrene 8% cross linked with Divinylbenzene”. In other words, small plastic beads. As most of us know, plastic does not deteriorate very much over hundreds of years. Plastic is one of the largest problems we have with landfills at this time. It does not go away. The same thing occurs with water softener resin media; it lasts a very long time. But there are other factors involved with the performance of this media. First and foremost is friction. During the regeneration process that every ion exchange softener goes through, friction is created. If your softener’s media bed is set to regenerate every other day, that’s a great deal of backwashing friction created over the years. There is also the possibility of the presence of chlorine. Chlorine can eat away at the smooth surface of these resin beads. And finally, there is the possibility of the presence of iron. Iron will adhere to these spherical beads and often times cannot be removed as efficiently as calcium is. Once your resin beads are coated with fine iron, they are nearly useless. If you are using your softener to remove iron, you can expect to replace your resin bed much more frequently than water without iron.

So when do you replace your softener’s media? When a simple hardness test strip consistently shows the presence of hardness downstream of the softener. Unless your softener is exposed to very high iron or chlorine, periodic testing for the presence of hardness should not start for 5-years after installation date. I have personally found softeners over 20 years old that were still removing hardness. If you are removing iron with your softener or exposing it to chlorine, I would start testing 1 to 2 years after installation, just to be sure.

Automatic Backwashing Filter Media: Depending on the media, this can be even more difficult to predict when to replace than softener media. Activated carbon media is porous and can not only trap contaminants in the water, it can also alter the chemical makeup of chlorine and organic chemical contaminants. As mentioned above, manganese greensand filter media has a fine coating on the media’s granules which trap iron particles. Sediment removal media such as Filter Ag can trap and hold fine silt or sand until backwashing occurs. Calcite is a type of water treatment media which slowly dissolves when low pH water passes through it.

Activated Carbon: There are literally dozens of different activated carbon filter systems out there. Some carbon media is designed to remove tannins (rotted, dissolved vegetation) from water. Other carbons are more suited to rendering chlorine inert, while others are designed to remove hydrogen sulfide. It is the manufacturing method and source material (coconut shell, wood, coal) that make up each carbon’s unique characteristics. Often called the “Taste & Odor Removal Media”, activated carbon in all its forms, makes your water taste much better than without. So how often should it be replaced? When the chlorine, VOCs or hydrogen sulfide you are removing with it starts bleeding through even after a recent backwash cycle has occurred. Test for chlorine or VOCs with a water test strip and check for the hydrogen sulfide with smell or taste.

Manganese Greensand Iron Treatment Media: Manganese greensand media removes iron and typically uses potassium permanganate as a regenerating oxidizer. As mentioned above, it has a thin coating of material on the granules which iron adheres to and hydrogen sulfide is oxidized. This media wears out when the thin coating wears off. The manufacturer does not suggest when this might happen. Simply test for the presence of iron in your water with a simple test strip shortly after and just before a scheduled regeneration takes place. You can try increasing the potassium permanganate dose per regeneration (see your owner’s manual for instruction) to get more performance out of the media, but this also increases operating costs. When iron begins bleeding through the filter media, it’s time to consider changing the bed.

Calcite: Calcite filter media is used to neutralize acidic water. Water with low pH (6.8 down to 5.5) can be passed through Calcite filter media to increase the pH level to a more neutral state of 7.0 – 7.4. As acidic water passes through the filter’s tank, the Calcite media dissolves. If left unchecked, the media will eventually dissolve away to nothing. Calcite media usually does not need replacement, rather it needs to be replenished every so often. That is why Calcite filters sold by us have a “dome-hole” at the top of the tank so that the control valve does not need to be removed just to add media. Calcite filters regenerate on a schedule to keep the media bed from becoming “caked-up” or channeled by water flow, but some Calcite filters may use a simple in-and-out head on them for the water to flow through. When using this type of filter configuration, it is possible for the media to “cake-up” and need replacing. This is a good reason for using a filter with an auto-backwashing control valve.

There are several other media types available for treating water problems, but the ones listed here are the most popular. Basically, once your softener/filter stops removing the contaminant in your water that it is designed to treat, that is a good indication it’s time to replace the media.