What is Reverse Polarity in a Salt Water Pool Chlorinator?

What is Reverse Polarity in a Salt Water Pool Chlorinator?

One of the benefits of a salt water pool system is the automation of pool chemistry and reduced workload by pool owners. But the addition of salt to the pool adds another component not found in a regular chlorinated pool, not to mention the extra equipment associated with a salt system. This equipment adds extra benefits and functionality including assistance with its maintenance.

Reverse polarity is a cleaning function and a major benefit of some salt water pool chlorinators. By reversing the electrical flow inside the salt cell, calcium deposits are removed from the metal plates and washed away. This makes salt cell maintenance easier and can also extend its life.

Let’s take a closer look at reverse polarity and the salt water pool chlorinator system more specifically.

How does a self cleaning salt water pool chlorinator work?

The reverse polarity feature is an automated cleaning function that comes with many modern salt water chlorinator systems so that you don’t have to manually clean the cell yourself. Not only is manually cleaning the cell a potentially messy and dangerous job involving chemicals like muriatic acid, you also run the risk of either not cleaning the cell correctly or damaging the cell in the process. As the name suggests, the process involves reversing the flow for a period of time to loosen and remove mineral build up from the metal plates of the salt cell.

By reversing polarity during the cleaning process, any deposits on the metal plates inside the cell are repelled and are forced off the plates and are then swept away by the strong water flow continuously being pumped through the cell and pool system. The cell is cleaned and when the cycle is complete, the flow is restored and the system operates again as normal.

The reverse polarity feature is automated and simply needs to be selected manually on your chlorinator to begin.

A salt water chlorinator operates with a Direct Current

A salt water chlorinator operates using Direct current (DC) which electrifies the salt in the water as it passes through the salt cell. The DC charge attracts deposits from the water pumping through the cell and over time, some will settle on the cell’s metal plates and attach themselves. Think of calcium and water deposits on your faucets particularly if you have hard water and no water softener.

As the deposits accumulate on the metal plates of your salt cell, it reduces the effectiveness of the cell and will eventually lead to it failing and possibly needing to be replaced prematurely. This is the value of the reverse polarity feature as you’d otherwise have to clean the cell manually yourself which is standard practice for pool owners with older chlorinator systems.

Let’s take a step back and explain a few of the parts of the salt water pool chlorinator system since they are specific to salt water pools and don’t exist in chlorine or bromine ones.

What is the salt chlorinator system and what does it do?

Traditional chlorinated swimming pools involve manually adding liquid chlorine, loose chlorine crystals or chlorine pucks that dissolve over time to sanitize and clean pool water, killing off bacteria and preventing algae growth. There is a great deal of manual work involved not only from the manual addition of chlorine but also the careful balancing of the various aspects of pool chemistry.

The invention of the salt water pool chlorinator system in New Zealand changed the way that pools are chlorinated and maintained by utilizing the principle of electrolysis to convert regular salt to a softer form of chlorine, and one without the associated strong smell of chlorine.

The salt water pool chlorinator system consists of two main components:

Salt water cell

The salt cell is a hard plastic removable tube that screws into the existing plumbing of the pool equipment near the pump. The inside of the cell features a series of parallel titanium blades that pool water passes over after being run through the pump. The process of electrolysis occurs involving a DC current and the presence of salt in the water that is added manually to the pool. The salt in the water gets converted into a form of chlorine that sanitizes the pool and keeps it clean for healthy swimming.

The salt cell is expected to last for several pool seasons (3-5 years is a ballpark range) before requiring replacement but its lifespan is affected by how well you take care of it including cleaning and maintaining it. The reverse polarity feature assists in this regard.

Salt water pool chlorinator main unit

The chlorinator main unit itself is the computer or control system that operates and runs the processes.

The main unit is typically a box with a computer inside that controls all the functions of the chlorinator system. While some systems are relatively small in size, other main units like Hayward chlorinator systems are larger and typically weigh 20 lbs – 45 lbs including the salt cell.

As we’ll see below, modern chlorinator systems can be automated to handle pretty much every aspect of your pool if you choose a model with the functionality. Some models also include phone app functionality for remote control.

Benefits of a salt water pool chlorinator’s automation functions

Among other things, a salt water chlorinator can automatically:

  • Monitor chlorine and salt levels and other aspects of pool chemistry.
  • Operate your pump, heater, lights and water feature on a timer and schedule.
  • Warn you with the use of sensors regarding poor water flow.
  • Monitor salt levels and warn you when it is too low or too high.
  • Shut chlorine production down when one of the above-mentioned faults is discovered.
  • Alert you to required maintenance and other problems.
  • Super Chlorinate your pool to add extra chlorine to the water before heavy swimming usage.
  • Operate and manage your spa or Whirlpool if you also have one.
  • Clean your salt cell with the reverse polarity feature so you don’t have to do it manually.

Popular salt chlorinator systems with the reverse polarity cleaning function

Many modern salt chlorinator systems come with a built in reverse polarity cleaning feature including:

  • Hayward Pro Logic
  • Hayward Aqua Rite
  • Hayward Saline C 6.0
  • Pentair Freeflo 25RP Pool Chlorinator
  • Zodiac EL-1 Saltwater Chlorinator
  • Zodiac Ei2 Mid Pool Chlorinator
  • Poolrite SureChlor S2500 
  • Davey ChloroMatic MCS50C
  • Davey ChloroMatic MCS24C
  • Davey EcoMatic DEM26C
Sky view of a unique shaped salt water pool in a backyard

How to reduce calcium build up on your salt cell

Salt is made of sodium and chloride and is also known by its chemical name NaCl. It’s the salt that is added to a salt water pool that actually helps to produce the calcium build up on the salt cell. A high pH level is the single largest reason why calcium builds up on your salt cell but there are other factors too.

With that in mind, there are a number of ways you can reduce the calcium build up on your salt cell and keep it clean.

  • Keep your pH level slightly on the low side and carefully monitor water chemistry in general. A pH reading of 7.2 – 7.4 is ideal.
  • Keep the calcium hardness on the low side too. Aim for 180 ppm – 200 ppm.
  • Monitor your Total Alkalinity level and keep it on the lower side, around 80 ppm – 90 ppm.
  • Use the self-cleaning reverse polarity feature of your chlorinator if you have one and stick to the factory setting which determines how long the feature should run.
  • Inspect the salt cell 1-2 times per swimming season by manually removing it and looking closely at the titanium plates to ensure they are in fact clean. There’s a video at the bottom of the page from Hayward that shows how to clean the cell manually if needed.
  • Run your salt chlorinator only as much as is necessary. Running it more than needed not only leads to the cell requiring replacement sooner, it increases your energy costs.
  • Use stabilizer to protect the chlorine and invest in a solar pool cover to shield the pool from the direct rays of the sun when not in use.

How to manually clean a salt cell (video)

Read the instructions for your specific chlorinator system and salt cell to familiarize yourself with their cleaning requirements. While a typical wash involves a combination of water and (muriatic) acid, some manufacturers may recommend something different.

Older and cheaper salt chlorinator systems with less functionality may not have the reverse polarity feature which means the pool owner has to do it themselves. It’s not a clean or fun job so take this into consideration when choosing a new chlorinator as the extra cost for a self-cleaning unit is worth the money.

My first chlorinator was an old school Lectranator salt chlorination system that had little functionality and certainly no automatic salt cell cleaning option.

Here’s a short video from Hayward showing you how you to manually clean a Turbo Cell without the reverse polarity feature.


Modern salt water chlorinator systems automate many aspects of pool care that used to be done manually. One particular benefit that is very helpful is the reverse polarity feature on some models which is a self-cleaning cycle for the salt cell.

Over time, minerals attach themselves to the metal plates of the salt cell which will degrade its efficiency leading to premature cell failure. The reverse polarity feature automates cleaning to take away a menial task that would otherwise be done manually with chemicals.

Carl Mueller

I bought a home with a salt water pool in 2006 and soon realized the benefits over traditional chlorinated pools. On this website I'll discuss all the tips and tricks I've learned over the years. I'll also help you troubleshoot various problems with pools in general and ones specific to salt water pools that I've experienced personally!

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