You are thinking of converting your chlorine pool to a salt water pool and want to know the difference. This article will give you the pros and cons of switching and the maintenance tips for both.
When you “convert” your chlorine pool to a salt water pool, in reality you are simply changing the way the water is sanitized. Both result in free chlorine being in the water at all times to kill any bacteria or other unwanted organisms.
How Chlorine Works in Traditional Pools
Typical chlorine comes in one of three ways; liquid chlorine (sodium hypochlorite), shock and tablets. Shock and tablets usually consist of the same ingredients, Trichloro-s-triazinetrione, or Tri-Chlor. Tri-Chlor has three parts; chlorine, muriatic acid (to keep pH in balance), and cyanuric acid which is used as a protection layer for the chlorine.
The Role of Cyanuric Acid in Pool Maintenance
Cyanuric acid, also known as stabilizer, protects chlorine from the harmful UV rays from the sun, especially during summer. However, it needs to be kept in a range, usually between 60-80 PPM, trying to make sure it doesn’t get above 100 PPM. Cyanuric acid acts like a bubble around chlorine molecules.
Too little of it present and there is no protection at all for the chlorine to stay in the water, and too much will “lock” the chlorine molecules up, unable to sanitize the water. I have seen pools where free chlorine is at zero and available chlorine is well above 5. Meaning that if the cyanuric acid wasn’t locking up all the chlorine molecules and you jumped in, your skin would start to dry out and your eyes would sting from such a high chlorine level.
That same pool was green with algae due to the high cyanuric acid level which “locked up” the chlorine, making it unavailable to keep the water clear. Any outdoor pool will need cyanuric acid checked and adjusted throughout the swim season to make sure the chlorine can effectively do it’s job of keeping the water safe and clear.
Methods of Introducing Chlorine into Pool Water
Chlorine can be introduced into the water in one of two ways under normal circumstances. One is with liquid chlorine, also known as sodium hypochlorite, and tablets that contain Tri-Chlor. If tablets are never used and levels are kept in balance with just liquid chemicals (chlorine and acid) then you will need to check and adjust for stabilizer once or twice a year, usually.
When using tablets it is important to remember that every tablet has some stabilizer in it and that can raise the cyanuric acid level to well above 100 PPM in less than a year’s time. If cyanuric acid gets well above 150 PPM, the only way to rid it from the pool water is to drain the pool. Usually a total drain is performed, but partial drains can also get the reading down into a manageable zone.
The Process of Switching to a Saltwater Pool
Switching to a saltwater pool is very simply making sure the total hardness, measured in PPM, of the water is not too high (adding salt adds calcium, which affects total hardness) and getting a salt cell, or chlorine generator, installing it at the right location in the system, and adding the correct amount of salt. If the water hardness is too high then you will need to drain the pool, usually fully, to bring the hardness level down.
It is usually recommended to start with fresh water when converting a pool from liquid or dry chemicals to salt as the previously added chemicals are not simply chlorine or acid, or Tri-Chlor. They add other minerals that are needed to bind them to keep them in either liquid or dry state for storage purposes. It is said that saltwater pools feel softer on the skin, so that is another reason to drain the pool completely and start with fresh water when converting to a saltwater pool.
How a Salt Cell (Chlorine Generator) Works
A salt cell, or chlorine generator, is simply a device that converts salt to chlorine using electrolysis. You want to make sure you size the unit to the size of your pool as too small of a generator will not produce enough chlorine to keep the pool properly sanitized.
Weekly and Seasonal Maintenance for Saltwater Pools
Once installed and the proper amount of salt is added to the water, weekly maintenance is simply checking the display of your generator (this may be on the unit itself, or a separate control panel) to verify the proper amount of salt is in the water and how much chlorine the unit is producing.
The hottest parts of summer will require higher chlorine production than spring or fall when the water is cooler. Keep in mind that most salt cells will not work in water below 60 degrees, therefore certain months of winter the generator will shut off to protect itself and you will need to maintain the correct amount of chlorine with either liquid or dry chemicals.
The small amount needed during this time will not negatively impact the water clarity or softness.
Cleaning and Maintaining a Salt Cell
It is recommended to clean the salt cell as often as cleaning the filter for the pool, which is every 3 or 4 months, depending on how quickly the filter gets dirty. It is common practice to clean the salt cell while cleaning the filter and this is done with an acid bath to the salt cell.
It will break down any residual calcium or salt build-up on the plates inside the generator making them ready to start producing chlorine again. Before taking the filter apart to clean, put the salt cell in the acid bath and by the time you are putting the filter back together after cleaning, the salt cell will be ready to be rinsed off and re-installed into the system.
Key Benefits of a Saltwater Pool System
One benefit of saltwater pools is that the system is producing chlorine anytime the water is filtering, whereas liquid chemicals are usually only added once a week, spiking the readings for a day or so, then loosing concentration the rest of the days until the chemicals are checked and adjusted. By producing chlorine daily, you keep the chlorine level at an overall lower level while still keeping the water more sanitized because the chlorine level stays at a much more constant level.
