One of the most common trends in the swimming pool industry over the last two decades has been the popularity of saltwater swimming pools.
For many years, to say anything negative about saltwater swimming pools bordered on blasphemy, but for the most part, pool industry professionals are now much more open about discussing the cons of saltwater systems as well. As a matter of fact, there are now many pool companies who refuse to install saltwater systems on swimming pools.
Hopefully the following information will help you to better evaluate whether a saltwater system is right for your pool.
What is a saltwater pool? A saltwater pool is a pool which has a purification system (also called a chlorine generator) that provides on-site production of chlorine.
Chlorine generators reduce the need to purchase and apply chlorine to your pool on a regular basis. Basically, instead of adding chlorine on a regular basis, you add salt periodically which is converted to chlorine by the use of electrolysis.
How does it work? The way it works is this: Salt is added to the pool and the saltwater passes through an electrolytic cell, where electricity is used to separate the sodium and chlorine molecules. This, in turn, produces hypochloric acid, the killing form of chlorine. Once the chlorine is used, it combines with sodium molecules and returns to salt and the whole process begins over again.
Oftentimes, pool companies tend to omit the cons when selling a saltwater system — and it is important that consumers understand the pros and cons of saltwater systems. Based on our experience, the following is a list of pros and cons of salt water systems:
Pros of saltwater pools
The feel of the water on the skin — This is probably the biggest advantage of a chlorine generator. Owners of chlorine generators talk about how soft and smooth the water feels.
Better water quality — Better water quality is maintained because the unit is chlorinating continuously when the pump is in operation.
Less eye irritation — Most report less eye irritation when using chlorine generators.
No need to purchase chlorine — Other than rare situations, there is no need to purchase chlorine. The exceptions to this are: chlorine generator is not producing enough chlorine (due to extremely high water temperature, heavy swimmer load, rain, etc.), chlorine generator is not working, chemical imbalance, etc.
No need to store and handle chlorine — Other than the rare situation listed above, storing and handling of chlorine will be limited.
Cons of saltwater pools
Initial cost — Chlorine generators are often sold as a cost-savings system, which is not a true statement in most situations. The installed price for a high quality residential chlorine generator is typically $1,500 to $2,000. True that you no longer have to buy chlorine — and salt is less expensive than chlorine — but at $1,500 to $2,000, you could buy chlorine for five to eight years.
Cell replacement cost — Chlorine generators are mechanical devices, and as with any mechanical device, they can break down. The most common failure of chlorine generators is the salt cell, which typically last three to five years (depending on use and maintenance) before needing replacement at an average cost of $600 to $800.
A saltwater pool is not chlorine-free — A saltwater pool is still a chlorine pool. The chlorine production in a saltwater pool is essentially sodium hypochlorite (liquid chlorine). If you are truly allergic to chlorine, then this is not the system for you.
Increase in electrical costs — A chlorine generator only produces chlorine when the pump is operating, so it is important to operate your pump a sufficient amount of time to produce the amount of chlorine that is needed for your pool. This amount of time will increase under the following conditions: high water temperature, heavy swimmer load, pets that swim, rain, chemical imbalance, etc.
Running your pump for longer periods of time will result in an increase in electrical costs. For example, a conventional 2hp pump in the Denton area costs approximately 25 cents per hour to operate. If you have to increase your pump run time from eight hours per day to 16 hours per day, that is an increase in your electrical costs of $2 per day, or $730 per year.
Salt can be corrosive — Salt can be corrosive to coping (especially flagstone), stone waterfalls, decks and any metal (diving board bases, pool ladders, slide legs, poolside furniture, stainless steel filters, firepits, etc.). To help slow down this corrosion process, the application of a penetrating sealer to coping and stone waterfalls seems to help. This penetrating sealer needs to be applied at a minimum of once annually. In addition, we recommend rinsing off your coping/decks/metal with fresh water after using the pool.
Not environmentally friendly — Due to the salinity of the water and its potential harm to sensitive plants and fish, many municipalities have restricted the backwashing or draining of saltwater pools into the storm sewer system.
They do not provide complete pool care — Oftentimes owners of saltwater systems depend on the system to provide complete pool care. They do not. Water testing and cell cleaning/replacement are very important.
Water testing — Chlorine generators only produce chlorine, they do not maintain the water chemistry of the pool. The pool water must still be tested and balanced as needed. We recommend the following testing regularity and ranges:
Test weekly: chlorine, 2.0 to 4.0 ppm; pH, 7.2 to 7.6; total alkalinity, 80 to 100 for calcium hypochlorite, salt and liquid chlorine pools, 100 to 120 for dichlor and trichlor pools; and salt level, 2,700 to 3,500 (check with the manufacturer of your chlorine generator to confirm).
Test monthly: calcium hardness, 200 to 400 ppm; and cyanuric acid, 30 to 90 ppm on chlorine pools, 70 to 90 on salt pools. It is also important to note that salt raises pH, which means more muriatic acid will be needed to keep the pH in the proper range.
Cell cleaning/replacement — Like any mechanical device, chlorine generators must be maintained. Most manufacturers recommend that the system's cell be cleaned every six months. Salt cells typically last three to five years, depending on use and maintenance. Salt cell replacement typically costs approximately $600 to $800, depending on the brand.
Scale-forming deposits on the tile/spa spillways/waterfalls — The use of salt can cause scale deposits to form on tile/spa spillways/waterfalls. Frequent brushing of these areas and use of a scale inhibitor are both recommended to prevent this scale buildup.
Does not work in cold water — Chlorine generators do not produce chlorine when the temperature reaches a certain level (approximately 55 degrees). When this occurs, the use of chlorine will likely be necessary in order to prevent problems.
Clearly, saltwater systems have both pros and cons, and if you are aware of them and take them into consideration, a saltwater system can be a very good alternative in the right situation.
MATT GOHLKE owns Gohlke Pools, which has earned national awards, certifications and recognition in the pool industry. He can be reached at 940-387-7521 or firstname.lastname@example.org.