Regenerating Water Filters: Using Dishwasher Salt for Cation Resin Cartridges

Water filters are essential devices that help remove impurities from water, ensuring clean and safe drinking water. Over time, these filters will become saturated with contaminants, leading to reduced efficiency. However, through the process of regeneration, water filters can be revitalized and reused, extending their lifespan and minimizing waste. In this post, I will explore how to regenerate simple cation resin cartridges using dishwasher salt, a cost-effective and readily available solution.

Understanding Dishwasher Salt

Dishwasher salt, also known as water softener salt, is a specific type of salt designed for use in dishwashers equipped with water softening systems. Unlike table salt, dishwasher salt is primarily composed of pure sodium chloride without any additives like iodine or anti-caking agents. Its main purpose is to regenerate water softeners by removing calcium and magnesium ions, which cause water hardness. This same principle of ion exchange makes it a suitable option for regenerating cation resin cartridges used in water filters.

Cation Ion Exchange and How It Works

Cation resin cartridges are used in water filters to remove positively charged ions from water, such as calcium (Ca2+), magnesium (Mg2+), and certain heavy metals. The resin within these cartridges is composed of small polymer beads, which are negatively charged and referred to as “cation exchange resin.” These negatively charged beads attract and trap positively charged ions as water passes through the filter.

As the cation resin beads capture these ions over time, they become saturated and lose their ability to efficiently filter water. This is where the process of regeneration comes into play. By using dishwasher salt, which is rich in sodium ions (Na+), we can trigger an ion exchange process to recharge the cation resin.

Regenerating Cation Resin Cartridges with Dishwasher Salt

Here’s a step-by-step guide on how to regenerate water filters with cation resin cartridges using dishwasher salt:

Step 1: Prepare the salt solution Take dishwasher salt and dissolve it in water to create a concentrated salt solution. The correct salt-to-water ratio is not that important. As a rule of thumb, make sure the cartridge is fully covered with a layer of salt.

Step 2: Fill the pitcher with tap water – add more salt if necessary. Just make sure it’s always covered with salt. The water should always be fully saturated with salt.

Step 3: Allow sufficient time Let the cartridge soak in the salt solution for at least 20 minutes.

Step 4: Give the Cartridge another run with salt solution. You can use the same water as used before.

Step 5: Rinse the cartridge After the soaking period, clean the cartridge from the salt solution and rinse it thoroughly with clean water. Rinse 3 pitchers or so. This step helps eliminate any excess salt and ensures the filter is ready for use.


Water filters (may) play a crucial role in maintaining water quality necessary to brew good coffee and tea. By understanding how to regenerate cation resin cartridges using dishwasher salt, you can prolong the life of your water filter and reduce the impact on the environment through reduced waste. It also helps you saving costs – OEM cartridges are not cheap! Regular regeneration helps your water filter perform optimally, providing you with clean and safe drinking water for an extended period. I guess this process can be repeated 3 to 5 times per cartridge before the resin degrades to an unusable level.