How Often do You Add Chlorine to a Saltwater Pool?


If you are responsible for maintaining a saltwater pool, you are in luck because these pools require fewer chemical gymnastics. But not all pools are built alike, and some are glorified hot tubs while others barely receive any salt yet feature a saltwater chlorinator. So, even though saltwater pools usually don’t need extra chlorine, some require it at specific intervals.

You add chlorine to a saltwater pool twice a month. Usually, you don’t add chlorine to a saltwater pool unless the pool is too big. If you add chlorine to aid the saltwater chlorinator in purifying the pool, you can add it in half the standard quantity and at one-fourth the regular frequency.

In this article, you will discover everything you need to know about saltwater pools and chlorine, including the role of chlorine in a regular pool, the role of salt in water, and whether chlorine is required in your swimming pool. Finally, you will learn the two types of chlorine injection methods and their respective frequency with regard to saltwater pools. Let’s get started!

Role of Chlorine in a Pool

While humans may drown in water, the compound itself isn’t chemically destructive to life. It is, in fact, conducive to growth and microbial propagation, especially when it is stagnant. Water, in the absence of movement, promotes the growth of algae and bacteria that can be harmful to one’s skin. However, corrosive chemicals that can kill bacteria are also harmful to human skin.

Chlorine is among the very few chemicals that check all the boxes. It kills bacteria and algae yet isn’t as harmful to the skin, at least in the recommended quantities. Most importantly, it is affordable, so it can be used frequently. Anyone who has owned a pool for a while knows that chemicals need to be added to its water on a regular basis.

Role of Salt in a Pool

When you look at natural bodies of water, you’re not likely to find chlorine-dense seas or oceans, but you will find salt almost everywhere. Salt, in sufficient quantity, kills certain microbes and makes water inhospitable for most bacteria and algae. Unlike chlorine, though, salt must be added in significant quantity to effectively eliminate bacteria. The role of salt in a pool is to be less effective, more natural, alternative to chlorine.

It is important not to confuse salt in natural water with salt in a saltwater pool. A saltwater pool is a pool that features a saltwater chlorinator. A salt-based purifier releases a slow stream of chlorine from the reaction of NaCl (salt) with H2O (water). Thus chlorine alongside the saltwater’s pH collectively makes the environment inhospitable for microbes. Still, with sufficient dirt and mismanagement, bacteria can grow in such a pool.

Should You Add Chlorine to a Saltwater Pool?

Now that you know that salt itself releases chlorine into your swimming pool, you might be wondering whether shocking the pool might be redundant. That is usually right. As long as your saltwater chlorinator is loaded and proportionate to the pool’s size, it can do chlorine’s job. However, if the chlorinator isn’t big enough to make the entire pool completely germ-free, you might need an assist from reliable chlorine.

You should add chlorine to a saltwater pool if the pool is large and you believe the saltwater chlorinator isn’t capable of getting rid of germs completely. Adding chlorine tablets will help you keep your pool clean, but you might shock the pool and revert to using salt only.

Chlorine use Frequency

Having identified two ways of using chlorine with a saltwater pool, let’s look at the frequency of chlorine addition in each. If you go with chlorine tablets, you will have to use them more often as opposed to shocking the pool, which is something you don’t frequently do. That said, please don’t base your decision on the frequency of either choice. Choose which type of chlorine addition is necessary for your pool, then commit to the regularity with which you’re supposed to add said chlorine to the saltwater pool.

Chlorine Tablets

You should add chlorine tablets to a saltwater pool once a week, albeit in a smaller quantity than you would add to a regular pool. The salt supply will be responsible for releasing the rest of the chlorine. If your pool is small, you can add chlorine tablets on a biweekly basis.

Pool Shock

You can shock a saltwater pool once a month and let the saltwater chlorinator eliminate any interim microbes. If your pool is larger than average, you might have to increase the frequency up to once a week. To save money and avoid over-chlorinating, you start with less-regular additions.

Chlorine Alternatives

There are chlorine alternatives available in the market, chief among which is bromine. You can add these in proportions recommended in the packaging. Remember, if you have an operational saltwater chlorinator, you need to add half the standard chlorine alternative and can afford to add it four times less often than the required frequency.

Is it Better to Have a Saltwater Pool?

In case you read this article in order to assess how much money you would save on unbought chlorine, you might still not have a complete picture regarding saltwater pools. While you might save money not buying as much chlorine, you will need to pay more upfront. More importantly, you will need a technician every time something goes wrong because of how complicated these pools are. Ultimately, the verdict regarding how good or bad a choice such a pool is depends on your context and preferences. All in all, saltwater pools aren’t inherently superior to standard pools.

Final Thoughts

Saltwater pools have free chlorine from salt’s reaction with water. However, the amount of said chlorine can drop below 1 ppm, which is when the addition of chlorine via tablets or powder is necessary. It is safer to take a reading once a week, but usually, you can get away with adding chlorine twice a month to a saltwater pool of medium size. For a larger pool, you require more frequent doses, and for smaller ones, you might skip shocking the pool altogether.

Jed Arnold

Jed spent every year from the ages of 15 - 22 as a Lifeguard (Red Cross) and ages of 17 - 22 as a Certified Pool Operator (CPO). Between working for over a dozen facilities and owning a pool, he carries over a decade of pool experience.

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