What Chemicals Are Used in Water Softeners?

A softener is a system that removes hardness minerals from your water supply and allows you to use softer, more palatable water for drinking, cooking, cleaning, and other purposes. The water softener works by ion exchange, which reduces or eliminates the dissolved calcium and magnesium salts that cause hardness in water.

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Ion exchange uses resin beads to capture the ions in hard water, such as calcium and magnesium and then swaps them for sodium ions. The sodium ions in the resin are polar opposites to the ions in the hard water; therefore, they attract each other and stick together. 

The ions in the water are then carried out of the softener to be flushed down the drain. The resin is regenerated when it has reached its capacity of holding hardness ions; this process involves a flow of sodium chloride brine solution, which reverses the ion exchange and effectively removes any remaining hardness ions from the water. 

Using a softener will also help prevent the buildup of scale, which is a chalky layer formed from soluble calcium and magnesium bicarbonate deposits. Scale not only clogs pipes but also reduces the lifespan of many household appliances like dishwashers, shower heads and water heaters. 

In some cases, the ion exchange process can also remove other cations (positively charged ions) such as iron and manganese from your water supply. If these other ions are present, a regenerate can be added to the softener’s water supply to reduce the number of minerals left in your drinking water. 

There are several types of chemicals that can be used in a water softener. Some of the most common include ResCare, which is designed to clean and rejuvenate the water softener’s resin; Rust Out, which helps prevent rust and iron from forming in the resin; and Potassium Permanganate, which can help regenerate the greensand plus in your water softener. 

These chemicals are typically added to the water softener’s brine tank after a regeneration cycle has been completed, but they can be added to the water as well. It’s important to read the instructions for adding any chemicals to your water softener, as they can be harmful if not properly used and handled. 

Ion Exchange Beads

During the ion exchange process, water flows through a bed of small plastic resin beads saturated with sodium ions. The ions in the water — calcium and magnesium — have a negative charge, while the sodium ions have a positive one. Because of this, the ions in the water are attracted to the ions in the resin. 

The ions in the resin are then trapped inside the beads, and a stream of sodium ions is released into the water to balance out the charge. The ion exchange process occurs again and again until the resin has completely exhausted its capacity of holding hardness ions. 

When the resin has completely been exhausted, it needs to be regenerated to replace the calcium and magnesium ions with sodium ions. During this process, the resin is coated with a sodium chloride brine solution and then flowed through to the water supply line and out into your home.