You’ve probably heard about using baking soda in a pool, but what does it actually do for your water?
There’s a lot to uncover. We break it all down in this article.
Quick answer: Baking soda, or sodium bicarbonate, is mainly used to raise the total alkalinity in a pool, which stabilizes the pH level. It can also be used to clean surfaces and soften the water, but there are better alternatives.
What Does Baking Soda Do for a Pool?
You may have been told that baking soda can be used for a number of different pool care applications.
These applications include:
- Raising your alkalinity
- Raising your pH level
- Killing off algae blooms
- Cleaning surfaces
- Preventing corrosion
- Softening the water
In reality, many of these are half-truths while some are just outright lies.
Let’s tackle them one by one.
Does Baking Soda Raise Total Alkalinity?
Yes, baking soda raises total alkalinity in a pool.
This is by far the most widely used application for baking soda when it comes to pool maintenance. This is because it quickly and effectively raises the total alkalinity with little downside to your water chemistry.
The benefit of keeping your total alkalinity high enough (between 80 and 120 parts per million) is that it acts as a pH buffer, absorbing changes in the water and preventing drastic fluctuations in your pH level.
In other words, when your total alkalinity is properly balanced, it makes keeping your pH level in check infinitely easier.
We wrote all about how to use baking soda to raise your alkalinity, and we also have a chemistry calculator that gives you exact dosages if you just want the hard numbers.
Did you know, baking soda is the primary ingredient used in many of the ‘alkalinity increaser’ products at your local pool store. It’s the exact same thing in a different, more expensive packaging.
Does Baking Soda Raise the pH Level?
Yes, baking soda raises pH in a pool, but only slightly.
Sodium bicarbonate, or baking soda, has a pH level of around 8, which means it’s going to slightly increase the pH level of any pool with a normal pH level (between 7.2 and 7.8).
Overall, it isn’t nearly as effective at raising pH as it is at raising total alkalinity, so it makes little sense to use it as a pH increaser unless you’re specifically looking for a small pH bump while significantly raising alkalinity.
On the other hand, soda ash (washing soda) will significantly raise both your pH level and your total alkalinity, while Borax will significantly raise your pH level with minimal impact on your total alkalinity.
Does Baking Soda Kill Algae?
No, baking soda does not kill algae.
At the very most, baking soda helps to prevent algae from forming by maintaining a high enough pH level in the water.
Algae prefer more acidic conditions, so maintaining a pH level above 7.2 is one of your best weapons when it comes to prevention. Since baking soda will help to stabilize your pH and even provide a subtle boost, you could argue it plays an indirect role in terms of algae prevention.
If you already have algae, no amount of baking soda will kill it. Instead, you’ll need to super-chlorinate (or shock) your pool by adding a very high dose of chlorine and letting it work overnight.
Does Baking Soda Clean Your Pool Surfaces?
Yes, but it’s rarely the best option.
If you put in enough elbow grease, baking soda will likely work for light stains, including general grout and grime
With that being said, unless you’re specifically looking for a natural solution, there are almost always better options for cleaning pool tiles and other surfaces, especially if you’re dealing with tough stains.
For example, if you’re trying to remove mild calcium scaling caused by a high level of calcium in the water, you’ll have better results using a pumice stone and a firm brush.
If you’re trying to remove metal stains caused by high levels of iron, copper, and manganese, you’ll be lucky to see any change using baking soda. Ascorbic acid (vitamin C) is a far more effective solution.
And even if you’re trying to remove organic stains caused by leaves and other organic material, simply raising your chlorine level will break it down enough for a light brushing to finish the job.
Note: There’s also acid washing, which uses muriatic acid to remove bad cases of scaling or staining. This is considered a last resort since it requires at least partial draining and can damage your pool if not done correctly.
Does Baking Soda Prevent Corrosion in a Pool?
No, baking soda does not directly prevent corrosion in a pool.
Pool water becomes corrosive to metal when the pH level falls too low and becomes too acidic. In extreme cases, a low pH level in your pool will slowly corrode your metal fittings and fixtures as well as your equipment.
The idea behind baking soda “preventing corrosion” is simply that it acts as a buffer that helps to keep your pH level elevated.
Overall, the baking soda itself doesn’t do anything to directly prevent corrosion in your pool, it only prevents a low pH level that may, in some cases, eventually lead to corrosion.
As long as you monitor your pH level on a regular basis and make the necessary adjustments when it falls out of balance, the amount of sodium bicarbonate you add to your water is irrelevant.
Does Baking Soda Soften Your Pool Water?
Yes, but not in the traditional sense.
Hard pool water is water that contains a high level of minerals such as calcium or magnesium, which can lead to issues such as calcium scale or metal stains forming on your pool surfaces.
For high calcium hardness levels, in particular, baking soda will combine with the calcium in the water to form calcium bicarbonate, which doesn’t contribute to the hardness of your water.
This process converts and effectively “removes” some of the mineral content that makes the water hard, which means it also plays in role in softening the water in your pool.
Granted, this isn’t the same as actually removing the minerals from your pool, it can still help to prevent the issues mentioned above.
Can You Put Too Much Baking Soda in Your Pool?
Absolutely.
You can always have too much of a good thing, and an excess of baking soda will lead to various issues with the balance of your water.
The biggest issue is how it impacts your pH level.
While baking soda only slightly increases pH, an excessively high total alkalinity will cause your pH level to rise over time because the baking soda is absorbing any acid that would otherwise pull it back down.
When your pH level gets too high (above 7.8), the water will begin showing symptoms. The severity of these symptoms typically worsens as the pH level continues to increase.
Specifically, you’ll notice the following:
- Your chlorine becomes less effective, allowing algae and other contaminants free reign in your water.
- Your calcium starts to precipitate out, allowing calcium scale to deposit along your walls, floor, and equipment.
- Your water becomes harsher on your eyes and skin, making the pool less enjoyable to use.
The Bottom Line
While some pool owners also use baking soda to soften the water, clean pool surfaces, or even fight off algae blooms, it’s only mildly effective at these things and there are almost always better alternatives.
In short, the biggest benefit of baking soda in a pool is raising low alkalinity in order to buffer your pH level and keep it in check.
