Will Baking Soda Lower Chlorine Level In Pool?

Baking soda for excessive chlorine in the pool? This is a DIY hack that most of us have heard of at some point. And although it sounds like an easy and cheap fix to a common problem, there is a plot twist here: baking soda does not actually lower chlorine in the pool. It has no direct effect on the levels or concentration of the sanitizer whatsoever. 

So where did this popular belief come from and what can you do instead? In this article, I will walk you through every detail.

What Does Baking Soda Actually Do In Pool Water?

Baking soda, as we know it, is a chemical compound called sodium bicarbonate. This compound is strongly alkaline and has a pH value of far above 7.0. When added to pool water, it makes the water alkaline.

As most of us are aware, hydrogen peroxide is a popular chemical that is used for lowering pool chlorine levels. However, hydrogen peroxide is practically ineffective at low pH and needs an alkaline environment to do the job. Here is where baking soda can help. It raises the pH of pool water and allows hydrogen peroxide to act and lower the chlorine levels. 

In short, baking soda does not directly influence the pool chlorine level but merely aids other chemicals in lowering it. 

What Can You Use For Lowering Pool Chlorine Level?

Now that the myth surrounding baking soda is debunked, allow me to present an effective, economical and easy option for reducing excessive chlorine from the pool: Sodium Thiosulfate.

Sodium thiosulfate is a sodium salt, and acts as a chlorine neutralizer. This means that when it comes in contact with chlorine, they react and form an inactive salt and as a result the chlorine level drops. Moreover, it also decreases the level of combined chloramines in the pool.

In addition to being highly effective, sodium thiosulfate is superior to other means of lowering chlorine in terms of its budget-friendliness, ease of use and safety as well. Adding it to pool water has virtually no side effects.

How Much Sodium Thiosulfate Is Required For Lowering Pool Chlorine Level?

A little amount of sodium thiosulfate goes a long way when it comes to neutralizing and reducing the chlorine level in pool water. To lower the chlorine by 10 ppm, you will need one cup of sodium thiosulfate for every 5000 gallons of water.

This equates to approximately 1.5 ounce per 1000 gallons of water. With this knowledge, you can calculate the amount of chemical you need, depending on your pool’s water capacity and the amount of chlorine that you wish to lower. 

Sodium thiosulfate retails for a pretty low cost. A 5 pounds package costs approximately $22, which means that one ounce of the chemical is for around $0.27. This budget friendliness, together with the small quantity required makes it a surprisingly economical option. 

Important Considerations When Using Sodium Thiosulfate To Lower Pool Chlorine?

By now, it is evident that sodium thiosulfate might arguably be your best bet for combating high pool chlorine. However, a few points are of note here.

  • The amount of sodium thiosulfate added must be carefully monitored. An excess of it might result in total depletion of chlorine from the pool, making it unhygienic and unsafe.
  • Too much sodium thiosulfate might persist for a few days, as chlorine neutralizers dissipate at a slow rate. This can prevent chlorine levels from rising again and may present as a problem when you wish to sanitize your pool a few days later.
  • Sodium Thiosulfate reacts with chlorine to form a salt, which raises the overall salinity of the pool water. You should avoid using it if your pool salinity is already high, as too much salt will affect the absorption and efficacy of other chemicals and disrupt the chemical balance of the pool water.
  • Addition of this chemical compound might result in cloudiness in the pool water. This, however, is completely normal and does not need to be worried about. The cloudiness will disappear after some time. 

Product Recommendation

To make life easy for you, here is an excellent option for sodium thiosulfate that I have hand picked. 

Pool Dechlorinator Sodium Thiosulfate Pentahydrate 5 lbs by Cesco Solutions

Top recommendation due to easy storage…


  • Effective
  • Efficient 
  • Cost Effective 
  • User friendly packaging 
  • Lasts for a long time


  • Might lower water pH

This sodium thiosulfate from Cesco Solutions is among the top-rated ones available in the market, thanks to its superb quality and effectiveness. It lives up to its claims and lowers both chlorine and bromine in pool water, and that too, at a rapid speed.

The chemical comes in a budget-friendly bulk package which lasts for months to years. The packaging is also easy to use and handle, and presents no problem with storage.

If you are looking for ways to lower metal levels in your pool water, read How to Use Metal Out (Metal Remover) in A Pool?

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