If you have an excess amount of chlorine in your pool due to adding the wrong amount or type of chlorine, then you will want to lower it down to safe levels. You could (and should) use a chlorine remover to do that, but there is a myth that baking soda can do that job.
While baking soda has its uses as a home substitute for various pool chemicals and cleaning products, it is not a substitute for a chlorine remover. It alone does not lower the chlorine levels, but rather baking soda needs to be used in conjunction with sodium peroxide in order to do that. Alternatively, you can just use sodium thiosulfate, a dedicated chlorine remover, to get the job done reliably as well.
In this article, we detail the ways that baking soda does affect your pool, the true way that you can affect your pool’s chlorine levels with baking soda, and how to accomplish this.
What you should know about baking soda
A little bit of contextual information about baking soda. It’s a chemical compound called sodium bicarbonate, it is strongly alkaline, and it has a pH value of 8.3-8.6; much higher than the 7.2-7.8 pH the pool needs to be at. When added to water, it makes it alkaline. But does it lower the chlorine level?
Does baking soda neutralize chlorine?
The simple answer is that it does not lower the chlorine levels one bit. What it will do is increase the pH and alkalinity of your pool as it dissolves.
How baking soda interacts with chlorine is that, rather than lower its levels, the increase in pH can render the chlorine ineffective if you have insufficient stabilizer.
The chlorine in the water will be affected by the change in pH (and not the baking soda directly), turning it from its effective HOCl form (hypochlorous acid) to its ineffective OCl form (hypochlorite ion). This renders the chlorine unable to kill the germs and bacteria in the water.
So even though baking soda does not affect the chlorine levels, it affects the concentration of effective chlorine and reduces its ability to sanitize your pool. This is not the result you were hoping for, is it?
Then how do you lower the chlorine level?
While baking soda does not lower the chlorine level, the increase in pH level caused by the baking soda can have a catalyzing effect on the chlorine if you combine it with pool-grade hydrogen peroxide.
Hydrogen peroxide is a chemical that removes chlorine, but it leaves the water acidic. Furthermore, it is ineffective at low pH levels and needs an alkaline environment to do its job.
Baking soda, on the other hand, makes the water more basic. Wait a minute. Combine baking soda with hydrogen peroxide to provide the alkaline environment needed, and you have the recipe for an effective chlorine remover.
Appropriately using baking soda with hydrogen peroxide to maintain a safe pH throughout the treatment process can caues the chlorine in the pool to evaporate and degrade at faster rates, effectively lowering the chlorine in the pool.
It is important to keep in mind that you need both baking soda and hydrogen peroxide. Alone, they can cause undesirable side effects by making your pool either too basic or acidic respectively.
Furthermore, since this treatment process requires you to buy pool-grade hydrogen peroxide in bulk, it might be less of a hassle to specifically buy a product specifically designed to lower chlorine instead.
How to lower chlorine in your pool without baking soda
One such chlorine remover that can reduce high concentrations of chlorine to safe levels is sodium thiosulphate. It is designed to help pool owners lower the chlorine level with minimal to no side effects.
The great thing about sodium thiosulphate is how safe it is. Depending on the concentrations used, you may still be able to swim in the pool even as it is being treated. However, carefully read and follow the instructions on the packaging to learn if your product allows for that.
Depending on the chlorine remover, you may not need very much product to treat your pool. A highly potent one may require only 50 grams of product to decrease chlorine levels by 1 ppm, assuming the pool holds 50,000 L of water.
Still not sold on it? Sodium thiosulfate is not only effective at chlorine removal, but budget-friendly as well. As mentioned, with hydrogen peroxide and baking soda, you’d need to buy these products in bulk to achieve the same results as a little bit of sodium thiosulfate.
Compared to sodium thiosulfate, 5 pounds costs $20-30, and so you’re only using like $0.3-0.5 dollars per use to lower the chlorine level? Overall, it’s easy to use, affordable, and effective – what more can a pool owner ask for?
Why sodium thiosulfate is the better option
While combining baking soda with hydrogen peroxide is a viable option, by now it should be quite clear that sodium thiosulfate is the superior option. Is there anything, then, that you should know about using this product?
First, while the product is generally regarded as safe, you should still carefully read the instructions on how to use it. Adding too much can completely deplete the chlorine level and leave the pool unhygienic and unsafe.
Next, if you add too much sodium thiosulfate, know that it can persist for multiple days since chlorine neutralizers dissipate at a slow rate. This can keep the chlorine levels low in the meantime and may make it difficult to sanitize your pool a few days later.
Another tip to keep in mind is that sodium thiosulfate will react with chlorine to form salt, thereby increasing the salinity of your pool water. Too much salt can interfere with the efficacy of other chemicals you add and may disrupt the balance of your water chemistry.
Lastly, adding sodium thiosulfate can temporarily make the pool water cloudy. This is to be expected and not a concern. The cloudiness will disappear on its own after a while.
The bottom line
Adding baking soda to the pool does not lower the chlorine level. What it does do is increase the pH and alkalinity, and it can be used as a cleaner for cleaning filth off of your pool walls or pool accessories. It is not a fix-all solution for adjusting your water chemistry.
In order for baking soda to be effective at lowering chlorine, it must be paired with products or chemicals that are acidic so that it can counteract the acidity and regulate the pH levels. Hydrogen peroxide and baking soda are one such example.
If your goal is to lower chlorine levels, then rather than rely on DIY solutions, the most effective way is to purchase and use a reliable chlorine removal product that is designed for this purpose.
Often, you do not need very much chlorine remover, and some may even allow you to continue swimming in it as it’s treating the pool.