Equipment and field

How to Clean a Salt Cell Without Damaging It

When to clean a salt chlorine generator cell, how to inspect it, how to acid wash it safely, and when to leave the work to the maker or an electrician.

A salt cell that is scaled over makes less chlorine, and the pool gets a callback. A cell that is cleaned too hard or too often wears out early. The goal is to clean it only when it needs it, by the maker's method, and to fix the water so it does not scale again.

Check the basics before you pull the cell

The cell light or error code does not always mean scale. Run through these first.

• Salt level. Test it with a reliable meter or strips made for it. The range is usually 2700 to 3400 ppm, but follow the cell maker.
• Flow. The pump should be running, the filter should be clean, and the valves should be open. Most cells shut off with low flow.
• Water temperature. Many cells reduce output or shut off in cold water. Check the manual for the cutoff.
• Output setting. Confirm the percentage is where the customer or you set it.
• Chemistry. CYA for salt pools commonly runs 60 to 80 ppm, so a pool that reads 20 ppm CYA will lose chlorine fast no matter how clean the cell is. See salt pool service.

If those check out, inspect the cell.

Inspect the cell

1. Turn the generator off at its control. If you are going to disconnect the cell wiring, also turn off power to the unit at the breaker.
2. Turn the pump off, then unscrew the unions and remove the cell. Water will drain from the line, so have a bucket ready.
3. Look at the plates. White or gray flaky buildup between them is scale. A little light scale is normal.
4. Check for damaged plates, a cracked housing, melted wire terminals, or brown corrosion at the connector.

If the connector is burned, melted, or wet inside, or the generator trips the breaker, stop. Do not touch it further. Turn off the power and call the cell maker or a licensed electrician. Electrical faults near water are not a place to improvise.

Clean in this order

Start with the mildest method that works.

Rinse and flake

1. Rinse the cell with a garden hose.
2. If scale remains, use a plastic or wooden tool to knock off loose flakes. Never use a screwdriver, wire brush, or metal pick. The plates have a coating and scratching it ends the cell's life.

Acid wash when scale remains

Only do this if the maker's manual allows it. Some makers specify a particular cleaner or a cleaning stand.

1. Work outdoors, with gloves, splash goggles, and clothes you can wash.
2. Use a plastic bucket or the maker's stand. Pour the water in first, then add the acid to the water. Many manuals give a ratio of about 4 parts water to 1 part muriatic acid, but ratios differ. Use your manual's.
3. Keep the cell wire end out of the solution. Fill only to the plate area.
4. Soak for the time the manual gives, which is usually a few minutes. Stop when fizzing slows. Do not leave a cell soaking for a long time.
5. Rinse the cell thoroughly with clean water.
6. Dispose of the used solution by your local rules. Never pour it into the pool or mix it with chlorine, and never store it in a closed container, because the solution can off-gas. Follow the product label and SDS.

Reinstall

1. Check the O-rings or gaskets and lubricate them with a pool-safe lubricant.
2. Hand-tighten the unions and keep the cell oriented the way the flow arrow shows.
3. Reconnect the cord, switch power back on, and start the pump.
4. Confirm there are no leaks and no fault light on the unit.

Hydrogen gas collects in a cell with no flow. Do not run the generator with the pump off or the cell removed.

Stop scaling at the source

Scale comes from the water. A cell that scales every few weeks is telling you the water is scaling.

Use the saturation index calculator on pools that keep scaling. A reading well above +0.3 points to scaling water. Aim for -0.3 to +0.3.

Many cells reverse polarity to shed scale as they run. That helps, but it does not replace water balance.

Set a route habit

Inspect the cell at a set interval, such as every few months or what the maker recommends. Put it in the customer's notes with the date. Take a photo of the plates when you inspect, so you can compare over time.

For example, with 40 salt accounts and a three-month interval, that is about 13 inspections a month. A cell that stays clean for two inspections in a row can be put on a longer interval, while a cell that scales fast needs the water fixed.

Mistakes to avoid

• Scraping with metal tools. It strips the coating.
• Soaking too long. Over-soaking removes plate material along with the scale.
• Washing on a calendar. Clean when it needs it, not because it has been a month.
• Adding water to acid. Always add acid to water, wear splash goggles, and never mix with chlorine.
• Ignoring the wiring. A burned connector means stop and call a pro.
• Running with no flow. Gas builds up in the cell housing.