I was visiting some friends this weekend in Phoenix, and noticed his swimming pool to be a little dark and cloudy.
“Yeah, it went green a few weeks ago – I shocked it, but I can’t get the water to clear”, Brian said.
We tested the water, found the chlorine level to be zero. Brian has a SWG (salt water generator), so we went right to the unit. The salt level in the pool was a bit low, but not by very much. “When’s the last time you cleaned the salt cell?” I asked.
When he looked like a little guilty, we loosened the unions on the salt cell and took a look inside the chamber. Arizona is known for hard water, so when we found calcium deposits between the plates of the salt cell, it was no surprise.
Cleaning your Salt Cell
The number one maintenance item for a salt water chlorinator is to clean the salt cell regularly, every 2-6 months, but only as needed. Mineral deposits bridge the space between the metal plates, and not just in hard water areas.
Calcium is naturally attracted to the electrically charged plates, and when they build up too much, it blocks the ability for electrolysis to occur. Over time, too much build-up on the salt cell can permanently damage the coatings on the plates, leading to cell failure.
Many new pool salt systems are self-cleaning. A great feature, they do this by reversing the polarity or charge of the metal plates, repelling the attracted mineral deposits, which is swept away by the rushing water, before it can attach to an oppositely charged plate.
We cleaned Brian’s salt cell by filling a small bucket with 1 gallon of water, mixed with 1 cup of muriatic acid. We submerged the cell in the bucket and left it for 10 minutes, then returned and flipped it over for a few more minutes.
We then flushed the cell with the garden hose, and could see clearly through the cell – that the deposits had been successfully removed. Afterwards, we dumped the acid solution into the pool. We then shocked the pool with granular chlorine to raise the chlorine quickly – it was after all, 108 degrees outside.
Some things NOT to do when cleaning your salt cell.
- Don’t soak the cell in acid for too long, over 20 minutes.
- Don’t increase the acid strength, use a 15:1 solution.
- Don’t use metal tools to scrape off salt cell deposits.
- Don’t clean the salt cell if it’s not visibly coated.
After the salt cell cleaning, we reconnected the unions and turned the filter pump back on, and noticed the glow of the “No Flow” indicator on the control panel. I checked the cable from the sensor to the control panel, which looked good, and it was also connected into the panel snugly. Time to inspect and clean the flow sensor.
Cleaning the Flow Sensor
Although rare, in hard water areas, the flow sensor can also develop deposits on the terminals. A flow sensor is used with salt systems to make sure that water flow is sufficient for operation. They also usually sense water temperature and the salt level in the pool, like the 3 sensor shown here.
After removing the sensor from the tee fitting, I scrubbed it with the textured side of a dish sponge, to clean all 3 sensor probes, or spots on the underside. We reinserted the sensor into the pipe and turned everything back on – still got the “No Flow” error!
We knew there was flow, since the pump was on, and there was 15 psi on the filter pressure gauge. “Time to clean the filter cartridges?” I asked. He said he usually waits until 20 psi to clean, but “sure, we can try that”. So, we pulled out the filter cartridges and took them over to the shade, had a seat to hose them off – they were very dirty.
Reinserted the filters, and started the system back up. The pressure gauge still read 15 psi, until I flicked it with my finger, and then it dropped to 10 lbs. We found the air bleeder assembly was clogged with debris, giving false readings.
Winter Salt Cell Maintenance
You may not know this, but most salt cells won’t work well in water temperatures less than 60 degrees. For this reason, they may have trouble creating enough chlorine in the winter, for sunbelt pools. They can also be overworked in such temperatures, leading to a shorter lifespan.
If your sunbelt pool temperature drops into the fifties, it would be best to shut off the salt system and use another chlorination method, like chlorine tablets, until the water heats up again.
For pools in the snowbelt, it may be advised to remove the salt cell after blowing the lines, and store it indoors. The sensor can also be removed, or it can be wrapped in plastic for the winter.
Other Salt Cell Maintenance Tips
Don’t overwork your salt cell – keep your chlorine level as low as you need to maintain clean and clear pool water.
Use Conditioner or Stabilizer, to help protect your chlorine level from the sun, and again, to prevent overworking your salt cell.
Keep your pH balanced, if below 7.2, it can etch the salt cell, and if above 7.6, it will reduce the chlorine’s effectiveness.
Keep the salt level proper in the pool. You’ll need to add more salt once or twice per year.
Pool Salt Systems are real time savers, but they do need occasional maintenance to keep them working properly, and to prolong the life of your salt cell.
Eventually, you’ll need a new salt cell. You’ll know it’s time when the chlorine output drops to low levels, despite a clean cell and sensor, proper water balance, salt levels and water temperature.
If you have any questions on salt chlorinator maintenance, leave a comment below, or give any one of our salty pool dogs a call for some help!
InTheSwim Blog Editor