Does Baking Soda Raise pH in Hot Tubs? (Yes, but this is better)

pH is one, if not the most important chemical balance to maintain if you own a hot tub. But with hot tub chemicals being a little pricey, many have wondered can I use baking soda to raise the pH in my hot tub?

Here’s what I know having owned hot tubs for the past 15 years:

Baking soda does work to raise the pH of your hot tub. But, it impacts alkalinity more than pH. Because of its minimal impact on pH, it can take over a pound of baking soda to significantly impact your pH. Soda Ash or magnesium oxide are much better alternatives for raising the pH in your hot tub.

But there’s a lot more to know about hot tubs and pH. So let’s keep going!

pH is a scale used to specify how acidic or basic a liquid is. Acidic solutions have a lower pH, while basic solutions have a higher pH.

Plain water is neither acidic nor basic and has a pH of 7. The pH scale ranges from zero to fourteen. But our bodies, oils, perfumes, other chemicals, and contaminants can alter the pH of water.

That’s why we have to continually adjust it.

If you do not correctly maintain your water’s pH, then you are unable to soak in it, because it is unsafe. There are different chemicals, tips, and tricks to maintaining your hot tub’s pH level. Read on to find out.

Is baking soda the best way to raise the pH in my hot tub?

No is the short answer. Soda ash or magnesium oxide powder, which I get into below, is a better option.

While baking soda can be used to raise the pH of your hot tub’s water, it will only raise the pH slightly.

Remember, the proper level for pH should be between 7.2 and 7.8 parts per million. Baking soda is mostly used to raise the alkalinity of your hot tub’s water.

If your hot tub’s pH level is too high, it can damage some of the equipment of the hot tub, such as the heater or pipes.

If you are still curious about the dangers of bathing in a hot tub with high pH levels, check out this recent article.

Just click that link to read it on my site.

Before using baking soda to raise the pH of your hot tub, you will want to first test the pH level of your hot tub’s water.

To do this, take a sample of the water and put a test strip in it. Wait a few minutes and check the color of the test strip with the color guide.

Low or high pH in your hot tub can lead to an increased chance to be exposed to harmful bacteria that can cause hot tub folliculitis or legionnaires disease.

Your hot tub’s water can also become cloudy, scale can grow, and your eyes and skin can become irritated, itchy, and red.

How much baking soda does it take to raise pH?

Baking soda (sodium bicarbonate) is near 8.4 on the pH scale, slightly above the neutral area of 7. Before using baking soda to raise your pH, use a test kit and see how high or low your pH is.

However, it is impractical to use baking soda to raise the pH level of your water. While it greatly increases alkalinity, it only raises the pH level by a little bit.

The farther from seven, the neutral area of the pH scale, your pH is, the more baking soda it would take to raise the pH.

One whole number is ten times the amount of baking soda used than the preceding number. The closer your pH is to 8.3, the more sodium bicarbonate you would need.

In fact, it would take 1.25 pounds of sodium bicarbonate to adjust a pH reading of 7.2 to a reading of 7.6. This is in a 600-gallon hot tub. It’s not a great idea to use baking soda to raise the pH level of your hot tub.

It’s better to use it for alkalinity.

Will baking soda also raise the alkalinity in my hot tub?

Baking soda can be incredibly helpful to homeowners who own a hot tub and want to raise your hot tub’s alkalinity levels.

What is total alkalinity?

Total alkalinity refers to how your hot tub’s water resists against sudden changes in the pH level. Your hot tub’s water alkalinity is one of the most important steps in managing your water and keeping it safe to soak.

The alkalinity level of your hot tub you want should be between eighty and one hundred and twenty parts per million.

Still confused about the difference between alkalinity and pH?

If so, check out this recent article to understand it better. What really surprised me was how one affects the other despite being totally different.

Just click that link to read it on my site.

If you want to raise the alkalinity of your hot tub’s water, use one tablespoon of baking soda per every one hundred gallons of water in your hot tub. For example, if your hot tub holds six hundred gallons of water, add six tablespoons.

Here is what to do to raise your water’s alkalinity with baking soda.

First, turn off the jets of your hot tub. Make sure you know the pH level of your hot tub by using a testing strip.

Add the amount of baking soda you need. This depends on the number of gallons of water in your hot tub or spa. Next, turn on the jets of your hot tub,  allowing the water to circulate. Keep the jets on for two to four hours.

Finally, test both the pH and alkalinity of your hot tub’s water.

Ensure they are at proper levels: between 7.2 and 7.8 parts per million for pH and alkalinity is between eighty and one hundred and twenty parts per million.

How do I raise the pH in my hot tub without raising alkalinity?

You can’t raise the pH in your hot tub without also raising the alkalinity.

It’s impossible not to raise both, but you can still raise one significantly and only raise the other by a little, depending on what chemical you use.

Both before and after raising your alkalinity, check both your pH and alkalinity levels.

If your pH is out of balance, scale can form, and the water can hurt you by creating itchy eyes and skin.

Is soda ash better than baking soda to raise pH?

Simply put, soda ash is much better at raising your hot tub’s pH level than baking soda.

Soda ash has a pH level of 11.4, while baking soda has a pH of 8.3. If you were to add baking soda to your hot tub, and the pH was higher than 8.3, it would actually lower the pH level.

Soda Ash is sodium carbonate compared to baking soda being sodium bicarbonate.

Soda ash will drastically raise your pH level, but it also raises your water’s alkalinity. Baking soda is the exact opposite.

So that is the biggest downside to soda ash – it also tends to raise total alkalinity a lot.

The only thing I know of that raises total pH without significantly impacting total alkalinity is called magnesium oxide powder.

Now to be sure, it does raise alkalinity a little, but not to the same degree as soda ash.

Magnesium oxide powder is concentrated too. So if you buy it, just know you won’t need to use as much of it as you would soda ash. Use about 2/3 as much magnesium oxide as you would soda ash.

So for the average size hot tub, that means starting with about 1/4 cup of magnesium oxide powder. You can always add more, but if you overdo it, you’ll have to add something to drop it back down.

Also, remember that turning the jets on will also raise your pH a little bit too due to the aeration.

So if you need to raise pH without significantly impacting alkalinity, check out the Bulk Supplements brand of Magnesium Oxide powder on Amazon Prime.

It has excellent reviews, a great price, and 1 bag will last hot tub owners quite a while. 2 lbs for about 20 bucks, and it comes with free Prime shipping.

Just click that link to see it on Amazon.

Did I cover all you wanted to know about using baking soda to raise the pH in your hot tub?

Baking soda is a home item that can be used to affect both the pH and alkalinity of your hot tub’s water.

Baking soda will mildly increase pH while substantially increasing alkalinity. There is no way to not raise both, but you can raise one more than the other depending on what you use.

However, baking soda is better used to raise your hot tub’s alkalinity level and not the pH. Soda ash is better suited to raise your hot tub’s pH level.

If your hot tub has low total alkalinity and good pH, use baking soda. But if you have low pH and good total alkalinity, use soda ash or magnesium oxide powder.

If you want to raise the alkalinity of your hot tub’s water, use one tablespoon of baking soda per every one hundred gallons of water in your hot tub (about 6 tablespoons for most regular-sized hot tubs).

These include damage to your spa’s equipment, itchy eyes and skin, cloudy water, scale, and an increase in the chance of unwanted bacteria and disease surviving in your hot tub.

Confused about hot tub chemicals, which ones are best, and what is best for sensitive skin?

Make sure and check out my ultimate guide to hot tub chemicals in this recent article. I cover everything you need to know including what chemicals you don’t need that are a waste of money.

Just click that link to read it on my site.


Photos which require attribution:

Arm & Hammer Pure Baking Soda (15 lbs.) by Lucille Martinez is licensed under Public Domain

 

Jeff Campbell

Jeff Campbell is a husband, father, martial artist, budget-master, Disney-addict, musician, hot tub lover, and recovering foodie having spent over 2 decades as a leader for Whole Foods Market.

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