Saltwater pools started to soar in popularity in the mid-2000s. Around the same time, reports of problems involving deterioration of stone copings began to emerge. Softer, more porous stones, such as limestone, were reportedly experiencing erosion on pool copings and deck areas where there was consistent saltwater contact. Some owners noted handrail and ladder anchor corrosion. However, saltwater pool owners love the less-rigorous maintenance routine and the greatly-reduced chlorine odor, as well as the lack of reddened eyes and less dried-out skin. While saltwater pools are undoubtedly gentler on the skin and eyes, are they tougher on your pool’s surfaces?
Not necessarily. It’s extremely important to monitor your water chemistry regularly. If your salt level is too high, it will react with the pool’s surfaces much faster. When your saltwater pool appears to be clear and there is no chlorine odor, you may mistakenly believe that all is well. However, your chlorine levels may be much higher than they should be. Saltwater pool water can become too acidic if not properly monitored and rebalanced as needed. Acids are known to deteriorate concrete. Insufficient or improper maintenance is the culprit, not the saltwater system.
A saltwater pool is still a chlorine pool in that chlorine is used to sanitize the water. The difference is that saltwater pools use salt and convert it to chlorine using a salt cell. Saltwater pools produce chlorine by circulating salty water through two electrically charged metal plates called the salt cell. Salt (NaCl) and water (H20) are converted into Chlorine (Cl2), Hydrogen (H2) and Sodium Hydroxide (NaOH) through electrolysis as the water passes through the energized salt cell. When the chlorine molecule has been depleted, the salt is converted back to NaCl, and the process begins again.
The energized plates of the salt cell attract calcium scale, which builds up on the metal surfaces. This will result in reduced chlorine output and eventually damage the cell. Salt cells require regular cleaning using a mild acid solution in order to dissolve this scale deposit. Today’s advanced inground salt systems are self-cleaning. This process is performed by reversing the polarity to the salt cell, causing shedding of the scale, which is then dispersed by the water.
It is vital for your water to be chemically-balanced. Salt concentration (salinity) and pH levels should be tested and adjusted, free available chlorine should be assessed, total alkalinity should be monitored, a stabilizer such as cyanuric acid should be used only if necessary, and total dissolved solids should be determined regularly.
Salt is a corrosive mineral. It can damage soft travertine stone or the stainless steel surfaces used on pool ladders, pool lights, etc. Over time, constant saltwater contact can pit or erode soft stone surfaces. Sealing surfaces around the pool, with regular cleaning for areas with low rainfall, can help protect soft surfaces from salt deposits. Proper adhesion between sealer and concrete prevents water from getting underneath the sealer. Penetrating sealers that will repel water may help prevent erosion issues. However, some sealers require more maintenance than standard patio applications. There can also be issues with slipping hazards around the pool from certain types of sealants.
If you have flagstone, tile, or concrete finishes in or surrounding your saltwater pool, it’s logical to expect some wear over time. Salt system manufacturers suggest rinsing salt-chlorinated systems frequently with fresh water after use to reduce the impact of saltwater on the concrete, stonework, or tile coping. Pool ladders, lights, and other stainless steel trim in the pool can also become cloudy and dull as salt oxidizes the steel. A sacrificial zinc anode can be utilized to combat the corrosion of metal items in your pool. Zinc anodes have a more active voltage than other metals and by electrically connecting an anode to the metal you would like to protect, the corrosion caused by the electrolysis will attack the anode first, hence the term, “sacrificial.” Sacrificial zinc anodes can be used in the pool or skimmer.
Salt can also cause deterioration of the soft rubbers used in pump seals and o-rings. However, salt-resistant pump shaft seals can be used. Also, pool lube can protect o-rings to extend their use.
It is important to keep an eye out for deterioration of any pool equipment you have running. You should not see salt crystals anywhere in your pool. If you see salt deposits beginning to grow on anything, there’s something wrong. Give your equipment immediate attention to prevent costly problems down the road.
While saltwater pools require less maintenance than a traditional pool, owners should not make the mistake of thinking no maintenance will be needed. However, with adherence to the appropriate routine or service from a reputable vendor such as Executive Blue Pools, you’ll spend less money and time concerned with the chemistry of your pool and a lot more time enjoying all the benefits.