How To Raise And Lower Alkalinity In Hot Tub


Proper alkalinity level is one of the essential things to keep your hot tub in a good condition for a longer period. It will maintain the quality of water and this way prevent any health issues or possible negative effects to your hot tub that could occur over time. In this article, we’ll show you how to how to raise alkalinity in the hot tub and how to lower alkalinity in the hot tub so you can get back to the hot tub party before you know it.

Total Alkalinity Explained

Before we start explaining how to raise alkalinity in the hot tub, it is important to learn what alkalinity is and why is it so important. The term “total alkalinity” is used to describe the total number of alkaloids in the water. By measuring total alkalinity, you’ll learn how much hydroxides, carbonates, bicarbonates, and other alkaloids your water contains. Total alkalinity is also different compared to pH levels by its measures; it is measured in parts per million, or ppm.

In simple words, if the alkaloid numbers are high, it is more likely your water is more stable and more resistant to pH changes because it will take more interference to change the alkaloids value, although too much of the alkaloids can also be bad for both you and your hot tub. The ideal value of total alkalinity is between 80 and 100 parts per million.

How Low Alkalinity Affects Hot Tub

Main alkalinity concern comes from its effect on the health of users, but it can also cause serious damage to many parts of your hot tub. The first one to feel the effect is the surface shell, which can get ugly coating or dots and spots along the surface, while its protecting layer will start to crack. Also, a low alkalinity level will take its toll on any metal object by increasing the chance of them corroding, which could lead to unrepairable damage to your heaters and other heating elements, pipes, and anything that has metal parts in them. Regular plumbing may help with this, but it is not a long-term solution.

Why You Should Raise Alkalinity

One of the main issues among the hot tub owners is their water becoming too acidic. Although connected and it does affect the overall level of acids and it is one of the main things that keep the water more basic, raising the alkalinity level is a bit different. By doing this, you’ll be increasing the amount of all alkaloids that are present in your hot tub – carbonates, bicarbonates, hydroxides, etc, this way allowing your hot tub to neutralize all the bad acids and keep pH levels steady.

How To Increase Alkalinity Level In Hot Tub

If you wonder how to raise alkalinity in the hot tub, the answer is – rather simple. It doesn’t take much of an effort, and just a bit of your patience before you’re able to use your hot tub again.

If you decide to go with fabric alkalinity increasers purchased from your local hot tub equipment shop or online, then all you have to do is simply follow the instructions provided by the manufacturer. That way you’ll get the best possible result. You could try various brands and types before you find the one that suits you and your hot tub the best. However, these chemicals may also lead to health-related side effects, so you should be extra careful not to use them over the recommended limit. If you do, you’ll probably have to not only drain and refill your hot tub but also clean it thoroughly.

The second way and the one we’ll focus on in this article is based on increasing alkalinity levels by baking soda. It is affordable, easy to get, the chance of it spilling and ruining anything or burning your skin while you use it doesn’t exist, and, most importantly, it works like a charm.

What You’ll Need

  • Baking soda
  • Water test strip
  • Tablespoon
  • Laptop or a tablet

Learn the hot tub capacity. This is directly related to the amount of baking soda needed for a successful job.

Turn the hot tub jets off.

Take a water test strip and test its pH value. Write your result down.

Take baking soda and add 1 tablespoon per 100 gallons of water.

Now it is time to turn the hot tub jets back on and let them spread the baking soda around.

Turn the laptop on and watch your favorite movie or TV show. It will take between 2 and 4 hours to wrap it up, so you could use that time to relax and enjoy something you love.

Once the movie is finished, take another water test strip and measure the pH level. If it is not between 7.2 and 7.8, repeat the process.

Once you reach the desired value, repeat the test after 24 hours. If the pH level is still the same, you’re good to go.

Additional Tips And Tricks

There are also some additional things you could do to reduce the usage of alkalinity. And if you want to read more about chemical-free hot tub maintenance, check out our guide.

Keep The Temperature Low

Lower the temperature of the water. The temperature of 94 degrees Fahrenheit should be enough for you to enjoy your bath completely, while your alkaline level will reduce at a twice slower rate than with the temperatures above 100 degrees.

Drain Your Hot Tub Regularly

The main thing that affects your hot tub condition is the freshness of water. As you use it, it becomes staler and it is easier for it to remain in good condition. You’ll help it by changing the water every week, instead of once or twice per month. This will remove any possible calcium carbonate buildup and keep the alkalinity levels optimal.

Distilled Water Instead Of Tap Water

Distilled water means there are no as many minerals that could affect the pH levels of the water. This doesn’t mean you should get distilled water in bottles, but you should check out the water distillation systems. They can be pricy but you’ll get better and healthier water in reverse, and it will be way easier to take care of the hot tub sanitization and other important aspects that will help you enjoy your hot tub better.

Cover Your Hot Tub

Another possible issue with alkalinity can come from all the things that can fall into the hot tub. To prevent anything from reaching the inside of your pool while you don’t use it, make sure you keep it covered when you don’t use it. This is especially important if your hot tub is in your bathroom, where even the smallest amount of any other chemical can cause a serious problem with your alkalinity level.

Lowering Total Alkalinity

If your alkalinity level is higher than 100 ppm and it has started to affect your pH level, it is time to reduce it a bit, and this is how to lower alkalinity in the hot tub. This is done by manufactured alkalinity decreasers which you’ll be able to purchase in a store or online. Just make sure to follow the instructions. Also, it is important to know that by decreasing the alkalinity level you’ll be also affecting the pH level, so make sure to test the hot tub water regularly, and perform at least one more test 24 hours after you’re finished with alkalinity decreasing.



Here are the answers to some of the most frequently asked questions about how to raise alkalinity in the hot tub:

Q: What can I use to raise the alkalinity in my hot tub? Can I use baking soda?


You could go with manufactured chemicals and alkalinity increasers, but using baking soda will be as equally efficient as all the other options, only healthier and less dangerous. So, the answer is yes, you could use baking soda.

Q: Should I raise pH or alkalinity first?


Start with alkalinity. Remember, alkalinity is basically an essential tool that will keep the pH levels on normal levels. When the alkalinity level is normal, it is time to take care of the pH level.

Q: What is alkalinity in the hot tub?


Alkalinity is used to describe the particles needed to fight and neutralize the acids from your hot tub. It is considered to be the most important aspect of keeping the pH levels optimal and prevents them from changing drastically.

Q: Is low alkalinity bad in a hot tub?


Yes, for both you and your hot tub. Spending time in a hot tub with high or low pH levels can be harmful to your skin and overall health, while the lack of alkalinity can lead to corrosion of metal pipes, heaters or heating elements, and it can also damage the surface of your hot tub.

Globo Surf Overview

Total alkalinity is an essential part of hot tub maintenance, so learning how to lower alkalinity in the hot tub and how to raise alkalinity in a hot tub is one of the most important things you’ll have to do if you want to enjoy your hot tub for a longer period. With this article, you’ll know what to do to make it as easy as possible. And also read about the best hot tub apps that will ease the maintenance process.

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Globo Surf
My name is David Hamburg. I am an avid water sports fan who enjoys paddle boarding, surfing, scuba diving, and kite surfing. Anything with a board or chance I can get in the water I love! I am such a big fan I decided to start this website to review all my favorite products and some others. Hope you enjoy!