Salt water pools are becoming increasingly popular. Unfortunately, so are myths and misinformation about salt water pools. In this article, we will take an in-depth look at how salt water pool systems work, their advantages and disadvantages, and clear up some common misconceptions about salt water pools.
How Do Salt Water Pool Systems Work?
Salt water sanitization systems work by adding regular table salt (sodium chloride) to the pool water. The salt water is then passed through a low voltage electric current. This current energizes the salt molecules which break apart and combine with the hydrogen found in the water to form a usable chlorine-based sanitizer.
As long as the system is running, and water is flowing through the “salt cell”, it will continue to produce these chlorine sanitizers; regardless of the current sanitizer levels present in the pool water. The rate at which the system produces chlorine is set by you. This allows you to change output levels as outside temperatures, and usage, change over the season.
What’s The Difference Between A Salt Water Pool And A Chlorine Pool?
In truth, there isn’t much difference between a salt water pool and a standard chlorine pool. In fact, the only difference is how they generate the chlorine needed to sanitize the water. It is important to understand that a salt water pool is still a chlorine pool. The salt water system is simply a way to generate chlorine automatically, rather than having to add it manually.
Benefits of Salt Water Systems
Improved Water Quality
The first benefit of switching to salt water is improved water quality. There are two reasons for this improvement:
- The effects of the salt itself.
- You’re not adding chlorine pucks.
Most chlorine pucks are actually less than 50% chlorine, with the balance being made up of stabilizers, binders, and other fillers. As these build up in the pool these byproducts can give the water a harsher, more “chemical” feel. By not needing to add any (or at least very few) chlorine pucks, you avoid that build-up; leaving you with a more natural feeling water. Salt water itself is also naturally “softer” feeling than fresh water; increasing this effect further.
Ease Of Maintenance
The other main benefit of switching to a salt water is the ease of maintenance. Since they produce their own steady supply of chlorine, you do not need to manually add chlorine in a salt water system, reducing your weekly maintenance time.
Another advantage of this consistent chlorine production is that you do not need to worry about your pool turning cloudy or green if you are away for several days or more. If the output is set properly, a salt water system should be able to maintain a proper level of chlorine in the pool water for 10-14 days without anyone needing to check in on it.
Drawbacks of Salt Water Systems
The main downside of a salt water system is the potential for corrosion. Salt water is more corrosive than fresh water. The more salt that is present in the water, the more potential for corrosion exists. To help combat this, many manufacturers have come out with low salt units. Hayward, for instance, has introduced the AquaRite Low Salt system which will effectively run at half the salt level that standard systems require.
Another drawback of salt systems is their tendency to slowly raise the pH of the water, which, if left untreated, can lead to scaling and water clarity issues. This pH climb can be easily combated by periodically adding a pH reducing chemical, usually once monthly.
This one is actually a benefit and a drawback. The water in pools equipped with salt water systems stays clear very easily. How can that be a drawback? While clear water is usually an indication that all is well, it can also be a sign of potentially serious problems such as:
- Very acidic water. Acidic water can look crystal clear, even if the water is far out of balance. If left untreated, acidic water can corrode metal components in the pool, pool pump, and heater as well as damage the finish of the pool with little or no visible sign that anything is wrong.
- High levels of chlorine. While it is easy to visually see when a pool has too little chorine (the water will start to turn cloudy or green), it is impossible to tell if there is too much chlorine in a pool simply by looking at it. Water with a high chlorine level is not only uncomfortable to swim in, it can also cause added wear and tear to the finish of your pool, as well as rubber o-rings and seals in the pool pump, filter, and heater.
Even if your pool water is crystal clear, make sure you test it at least once per week to confirm that the pH and chlorine levels are within range. If you notice that your pH is off, add some balancing chemicals to get it back in range. If your chlorine is too high, lower the output of your salt chlorine generator until the level is back within the normal range.
Some Misconceptions About Salt Water Systems
- Salt water systems are completely chlorine-free. As we’ve already seen that is not the case; they simply produce their own supply of chlorine. They also need to have some chlorine added at the beginning of the season and after heavy uses to maintain a safe level of chlorine in the pool.
- You need a special pump and filter to run a salt water pool. There is no such thing as a “salt water pump” or “salt water filter”; any pool pump or filter will do just fine. That said, it is a good idea to avoid heaters that have copper heat exchangers. While the salt itself will not affect any of your pool equipment, salt water pools do tend to have a little higher of chlorine and more variable pH level than standard pools. Both of these can cause copper to rust, leading to a shorter life for your heater and potential staining of the finish of your pool. Just to be safe, we recommend buying a heater with a titanium or cupronickel heat exchanger instead.
- All you do is add salt and it takes care of everything else. Again we’ve seen that that is simply not the case. While it does eliminate the need to manually add chlorine; the water still needs to be balanced and shocked every few weeks. Salt also needs to be periodically added as water splashes out and is replaced by freshwater.
- Salt systems will save you a ton of money on chemicals in the long run. While it is true that you will save money by not having to buy nearly as much chlorine, those savings are negated by the initial costs of buying the system, and the cost of replacing the salt cell every 5-7 years. When looking over the span of 10 or more years, the overall cost difference between using traditional chlorine and salt water chlorination is minimal. Salt water pools should be viewed as a time saver, not a money saver.
Other Salt Water Pool Tips
- Test your pool water 2-3 to ensure that you’re maintaining a good level of chlorine in the water. If the chlorine level is consistently too high or too low, adjust your salt water system accordingly.
- Generally speaking, the warmer and sunnier it is outside, the higher you will have to set the output of your salt water system. Likewise, when the water is colder and not getting much use, you should reduce your salt system’s output so that the chlorine level in the water doesn’t get too high.
- Salt water systems typically don’t work very well in colder water. If you open your pool early and the water is still cold, we recommend using chlorine pucks until the water is around 65 Fahrenheit.
- Remember, salt water pools aren’t maintenance fee pools. You still need to ensure the water is properly balanced, brush the walls of the pool, and shock it periodically, typically every 2-4 weeks, to prevent any problems from arising.