Saltwater pools are swimming pools that use a salt chlorine generator to produce chlorine from salt and sanitize the water. They are different from traditional chlorine pools that use chlorine tablets or granules to disinfect the water. Saltwater pools have some advantages and disadvantages over chlorine pools, such as lower annual costs, softer water, and less environmental impact. In this article, we will explain what saltwater pools are, how they work, and what are their pros and cons.
What is a Saltwater Pool?
A saltwater pool is a pool that contains salt in the water, usually around 3,000 ppm (parts per million), which is about 10 times less than the ocean. The salt in the water is converted into chlorine by a device called a salt chlorine generator, which is installed in the pool’s plumbing system.
The salt chlorine generator uses electricity to split the salt molecules into sodium and chlorine ions, which then react with water to form hypochlorous acid, the same substance that is produced when chlorine is added to a pool. Hypochlorous acid is a powerful sanitizer that kills bacteria, algae, and other contaminants in the pool water.
The salt chlorine generator also reverses the process of electrolysis, turning the hypochlorous acid back into salt by combining it with sodium ions. This means that the salt level in the pool remains constant and does not need to be replenished frequently unless there is water loss due to evaporation, splash-out, or backwashing. The only maintenance required for a saltwater pool is to check the pH and alkalinity levels weekly and adjust them if needed, and to clean the salt cell of the generator periodically to prevent calcium buildup.
Pros and Cons of Saltwater Pools
Saltwater pools have some benefits and drawbacks compared to traditional chlorine pools. Here are some of them:
Pros of Saltwater Pools
- Lower annual costs: Saltwater pools are cheaper to operate than chlorine pools, as they do not require buying and storing chlorine tablets or granules. According to various sources, a summer supply of salt for a saltwater pool can cost between $20 to $30 on average, while chlorine can cost around $150 to $180 for the same period and the same size pool.
- Softer and gentler water: Saltwater pools have lower chlorine levels than chlorine pools, which makes them more gentle on the skin, eyes, hair, and swimwear. They also do not have the strong chemical smell that many people dislike about chlorine pools. Saltwater pools can help maintain the body’s moisture balance and natural oils, and leave the skin feeling smooth and silky after a swim.
- Better for the environment: Saltwater pools do not emit chloramines, which are compounds that form when chlorine reacts with organic matter in the water. Chloramines can cause eye irritation, respiratory problems, and unpleasant odors. They can also evaporate into the air and contribute to air pollution. Saltwater pools have less impact on the environment than chlorine pools.
Cons of Saltwater Pools
- Higher initial cost: Saltwater pools have a higher upfront cost than chlorine pools, as they require installing a salt chlorine generator, which can cost around $1,400 to $2,000, plus installation. The generator also consumes electricity to run, which can add to the energy bill.
- Corrosion: Salt can be corrosive to some metals and materials that are exposed to the pool water or the generator. Saltwater pools may require using corrosion-resistant equipment and accessories, such as stainless steel or titanium. Salt can also damage concrete surfaces or natural stone tiles around the pool if not sealed properly.
- Complexity: Saltwater pools are more complex than chlorine pools, as they involve an electrical device that needs to be calibrated and maintained regularly. The generator also needs to be compatible with the pool’s size, shape, and pump system. If the generator malfunctions or breaks down, it can affect the water quality and safety of the pool.
What is the best pH Level for a Saltwater Pool?
The best pH level for a saltwater pool is the same as for any other type of pool, which is between 7.2 and 7.8. This range is slightly basic and ensures that the water is comfortable for swimmers, safe for the pool equipment, and effective for sanitizing. If the pH level is too low or too high, it can cause various problems, such as irritation, corrosion, scaling, or algae growth.
How to Test pH in a Saltwater Pool
To test the pH level in a saltwater pool, you can use a pool testing kit, such as a liquid test kit or test strips. You can also take a water sample to your local pool store for analysis. You should test the pH level at least once a week, or more often if there are changes in the weather, water temperature, or pool usage.
How to Adjust pH in a Saltwater Pool
If the pH level in your saltwater pool is too low (below 7.2), you need to raise it by adding a base, such as soda ash (sodium carbonate) or baking soda (sodium bicarbonate). Soda ash is more effective and faster than baking soda, but it can also raise the total alkalinity of the water, which is another important factor to balance. Baking soda is gentler and cheaper than soda ash, but it can also increase the total alkalinity and take longer to dissolve.
If the pH level in your saltwater pool is too high (above 7.8), you need to lower it by adding an acid, such as muriatic acid (hydrochloric acid) or dry acid (sodium bisulfate). Muriatic acid is more powerful and cheaper than dry acid, but it can also lower the total alkalinity of the water and be hazardous to handle. Dry acid is safer and easier to use than muriatic acid, but it can also reduce the total alkalinity and add sulfates to the water, which can damage the salt cell.
The amount of base or acid you need to add depends on the size of your pool, the current pH level, and the target pH level. You can use a pool calculator to determine the exact dosage based on these factors. You should always follow the manufacturer’s instructions when adding any chemicals to your pool, and wear protective gear such as gloves and goggles. You should also pre-dissolve the chemicals in a bucket of water before adding them to the pool, and pour them slowly along the perimeter of the pool while the pump is running. You should wait at least four hours before testing the pH level again and making any further adjustments.
How often should I add salt to my pool?
Adding salt to your pool is part of the regular saltwater pool maintenance that you need to do to keep your pool clean and clear. Salt is the main ingredient that your saltwater generator uses to produce chlorine, which sanitizes your pool water.
How often you need to add salt to your pool depends on several factors, such as:
- The size and capacity of your pool
- The salinity level of your pool water
- The output setting of your saltwater generator
- The amount of water loss due to evaporation, splash-out, backwashing, or leaks
- The amount of water added due to rain, refilling, or topping off
Usually, you only need to add salt to your pool once or twice a year, or when you open your pool for the season. That’s because salt does not evaporate or get used up by the generator. It only gets diluted or removed by water loss or replacement.
To know how much salt you need to add to your pool, you need to test the salinity level of your pool water regularly. You can use a salt test kit, a digital salt meter, or a test strip to measure the salinity in parts per million (PPM). You should aim for a salinity level between 2,700 to 3,400 PPM, depending on the recommendation of your generator manufacturer.
You can use a pool salinity calculator to find out how much salt you need to add based on your pool size and current salinity level. You should use pool-grade salt that is at least 99% pure sodium chloride and free of additives or impurities.
When adding salt to your pool, follow these steps:
- Check your generator manual for any specific instructions or precautions.
- Turn off the generator and turn on the pump to circulate the water.
- Pour the salt evenly around the edges of the pool, avoiding the skimmer and the main drain.
- Brush the salt gently to help it dissolve faster.
- Wait for at least 24 hours before turning on the generator and testing the salinity level again.
- Adjust the generator output setting according to the desired chlorine level.
Conclusion
Saltwater pools are swimming pools that use a salt chlorine generator to produce chlorine from salt and sanitize the water. They are different from traditional chlorine pools that use chlorine tablets or granules to disinfect the water. Saltwater pools have some advantages and disadvantages over chlorine pools, such as lower annual costs, softer water, and less environmental impact. However, they also have higher initial costs.