Saltwater Pool Troubleshooting
Saltwater pools experience many of the same problems that befall pools using traditional chlorine as the primary sanitizer. That said, there are some attributes that require attention in all saltwater pools, especially due to the unique way the sanitizer is produced. This includes balancing pH, maintaining chlorine residual and preventing scale. Each one of these frustrating issues can be prevented with proper maintenance.
Maintaining pH levels
In the process of generating chlorine in saltwater pools, pH in the water increases over time. This is a result of the byproducts created by turning salt into free available chlorine. Sodium hydroxide, which has a pH of 13.5, is produced in excess. This byproduct is responsible for the steady increase in pH in saltwater pools. These pools require routine pH adjustment as required. If left unchecked, high pH levels can lead to ineffective sanitizer, cloudy water, scaling, and algae.
Another issue saltwater pools may experience is failure to maintain a free chlorine residual. This is also a common problem in traditional halogen pools, but in saltwater pools the problem can typically be tracked down to one of two causes—either the pool is experiencing a chlorine demand, or the cell is no longer physically capable of producing enough free chlorine.
Meeting a chlorine demand
A chlorine demand is present when the pool shows the consistent inability to establish a sanitizer residual, caused by too many contaminants consuming the chlorine and not enough sanitizer in the water to oxidize these pollutants. Pools in a demand have no sanitizer available for bather protection. The chlorine generator cell often cannot make chlorine quickly enough to provide the amount needed to overcome the demand. If the need is large, an additional source of chlorine is required to break the demand and re-establish the sanitizer level.
There are times when a salt water pool may not be in a chlorine demand, but it still may not be able to maintain a free chlorine residual. Common causes for this include not running the cell generator long enough, an undersized cell that is unable to produce enough chlorine to keep up, condition or age of the cell and improper salt levels in the pool.
Scale deposits can also impact how well an electrolytic cell produces chlorine. Buildups are more likely to occur as the pH of a saltwater pool increases. Once the scale accumulates, it will reduce the ability of the cell plates to pass electricity through them. Electricity is the key to chlorine production. The higher the scale buildup, the less chlorine is produced.
Types of Calcium Scale
There are two types of calcium scale formations: calcium carbonate and calcium phosphate. Each accumulation is influenced by different factors. Calcium carbonate is the most common type of scale found within any pool environment and makes up the majority of buildups found on chlorine generator cell plates. These scale formations are influenced by three main factors: water temperature, pH, and concentration.
On the other hand, the formation of calcium phosphate scale is not driven by high pH. Higher concentrations of both calcium and phosphate, as well as higher temperatures in the pool will cause increased risk of calcium phosphate scale formation.
It is imperative to use a scale inhibitor product to help prevent buildups in both chlorine generator pools and spas. In addition, some manufacturers warn against high phosphate levels to prevent the calcium phosphate scale that may form in the chlorine generator. Adding a phosphate remover into the pool or spa maintenance routine can help reduce scale and improve cell efficiency.
Saltwater pools provide a premium experience to pool owners. However, a proper maintenance routine must be followed to prevent problems—the same issues often found in traditional chlorine pools that are resolved by similar activities. That said, some of the problems are exclusive to saltwater pools and require specific products or actions to fix them. The ultimate goal is to provide all pool owners with clear, pristine water, and saltwater pools are no different.