Using a Water Softener Resin Cleaner

What resin cleaners do

A salt-based softener works by ion exchange. The resin beads swap calcium and magnesium for sodium, and each regeneration rinses them with brine and flushes the hardness to drain. That brine rinse handles hardness well, but it does not fully remove iron and some other contaminants. Over months they coat the beads, and coated beads have fewer sites left to grab hardness.

The store text for Pro Products RES CARE-Q puts it this way: iron and other contaminants foul the resin and hurt ion exchange, and the cleaner chemically reduces that fouling and restores exchange capacity. The Pro Rust Out product page says the same about iron in particular: the iron build-up that coats a resin bed is not totally removed during normal regeneration, and the cleaner takes out what brine leaves behind.

Signs that the resin may be fouled include rising hardness in softened water, rust stains returning, and a slow loss of water pressure. The Fleck 5600SXT service manual lists iron buildup in the softener as a cause of pressure loss and says to clean the control, add mineral cleaner and regenerate more often. Before blaming the resin, rule out simpler faults with our troubleshooting guide and the low water pressure guide.

Iron cleaners vs general cleaners

There are two broad kinds of cleaner, and they are used differently.

A liquid cleaner suits most homes, whether the problem is a little iron on well water or general fouling. Quality Water Treatment sells RES CARE-Q resin cleaner (sold by Quality Water Treatment, our store) for routine and recovery cleaning of the resin bed through the brine well.

A powdered iron remover is built for homes that fight iron all the time. Quality Water Treatment's Pro Rust Out 50-lb container (sold by Quality Water Treatment, our store) is meant to be layered into the brine tank as you add salt, so every regeneration carries a little cleaner.

Neither type fixes iron the softener should not be handling. A softener can take out small amounts of dissolved, clear-water iron, typically a few ppm with suitable resin. Red or orange oxidized iron, iron bacteria, higher iron and a rotten-egg sulfur smell need a dedicated iron or sulfur filter ahead of the softener, so follow your softener maker's stated limits.

How to dose and run it

Doses below come from the product labels. Always read the label on the container you buy, since it wins over any summary.

RES CARE-Q, recovering a fouled softener. The label says:

1. Wait until the salt is low. The label says to add the cleaner when the salt level is low.
2. Pour 1/2 cup (4 oz) per cubic foot of resin into the brine well. The brine well is the tube in the brine tank that holds the float and brine line.
3. Start a manual regeneration. On a Fleck 5600SXT, hold Extra Cycle for 5 seconds to regenerate now; see the Fleck 5600SXT programming guide.
4. Repeat if needed. Run it again if the discharge still shows taste, odor or discoloration.
5. Flush. Run the nearest cold soft-water tap until the water is clear.

RES CARE-Q, routine use. For upkeep, the label's dose is 1 tablespoon (1/2 oz) per cubic foot, poured in ahead of every regeneration. Homes with an automatic feeder dose 0.5 or 1.0 oz per day.

Pro Rust Out. The product page says to layer 4 oz between each bag of salt.

To find the resin volume, look at the tank label or the manual. As a cross-check, Pentair rates its 5600SXT units at 31,100 grains for one cubic foot, 46,600 for one and a half, and 62,200 for two.

Keep cleaner and bleach as separate jobs. Bleach is for sanitizing against bacteria and odor, and our sanitizing guide covers that dose. Quality Water Treatment also warns against putting vinegar in the brine tank.

How often to clean

The stores give different schedules, so match the interval to your water and your iron level.

• Quality Water Treatment recommends a resin cleaner quarterly on its maintenance page.
• SoftPro puts Rust Out on a 3- to 12-month cycle.
• Quality Water Treatment's Fleck 5600SXT install guide ties cleaning to iron: anything over 0.3 ppm needs periodic cleaning, and clear-water iron calls for a resin clean twice a year, earlier if treated water starts showing iron.

In practice that means homes on city water with no iron may only need a cleaner when performance drops, while well homes with iron sit at the shorter end. If you use a routine dose before each regeneration, or layer Rust Out with every bag of salt, you are cleaning continuously.

Add the cleaning to the rest of your yearly routine in the water softener maintenance checklist. If cleaning no longer brings the hardness back down, the resin may be worn out, and the next step is replacing the resin.

Common questions

Keep the resin working

• MaintainRe-bedding with new resin
• MaintainBleach sanitizing, step by step
• FixChecking whether the softener works
• MaintainBrine tank cleaning
• MaintainThe full maintenance schedule