How To Lower Alkalinity In A Hot Tub – Easy Guide

Michael Keenan

Updated

Hot Tub Water Chemistry

Are you struggling with high alkalinity levels in your hot tub? Excessive alkalinity can lead to issues like green water and reduced sanitizer effectiveness, compromising the water quality. But don’t worry, there are steps you can take to lower the alkalinity and restore balance to your hot tub.

I’m going to guide you through the process of adjusting alkalinity step-by-step.

It’s important to understand what causes high alkalinity in a hot tub. I’ll explore the factors that contribute to this problem. Then, discuss why high alkalinity is a problem and how it affects your hot tub’s performance.

Next, onto the main topic – how to lower total alkalinity in a hot tub effectively. You’ll learn about different chemicals available to lower alkalinity and how to use them.

Lastly, I’ll share some helpful tips for managing hot tub alkalinity and pH on an ongoing basis.

By following these steps, you’ll be able to maintain optimal alkalinity levels in your hot tub for clean and enjoyable soaking sessions.

lower alkalinity in a hot tub

Key Takeaways

  • High alkalinity in a hot tub can lead to green water and reduced sanitizer effectiveness.
  • Alkalinity and pH are related but not the same, with alkalinity acting as pH’s buffer.
  • Alkalinity should be kept between 80-120 ppm in a hot tub.
  • To lower alkalinity, use sodium bisulfate or muriatic acid according to the amount of water in the hot tub.

I have a series of guides all about alkalinity in your hot tub. Start with the main one! Then see how to raise alkalinity in your hot tub and see what causes low alkalinity in hot tubs.

What is Alkalinity?

So, you’re wondering what exactly is alkalinity and how it relates to your hot tub. Well, let me tell you – alkalinity is like the bodyguard for pH, keeping your water stable and protected from acidification.

It’s the capacity of water to resist changes in acidity levels. Think of it as a buffer that prevents wild swings in pH. In other words, alkalinity acts as a defense mechanism for your hot tub water.

Maintaining the right level of alkalinity is crucial because if it gets too high or too low, it can cause all sorts of problems like green water, scale buildup, and reduced sanitizer effectiveness.

You should aim to keep alkalinity levels in your hot tub between 80 and 120 ppm (parts per million).

Now that you understand what alkalinity is all about, let’s dive into what causes high alkalinity in a hot tub.

What Causes High Alkalinity in a Hot Tub?

One of the main culprits behind excessive alkalinity levels in your spa is the water source you refill it with. If your water source has naturally high alkalinity, it can cause an imbalance in your hot tub.

Chemicals such as alkaline-based shock treatments or certain pH increasers can contribute to high alkalinity levels. Sweat, lotions, and other contaminants introduced into the hot tub can also raise alkalinity.

Now that we know what causes high alkalinity in a hot tub, let’s explore whether or not it is a problem for your spa.

Is High Alkalinity in Your Hot Tub a Problem?

Excessive levels of alkalinity in your spa water can lead to a wide range of issues that compromise its cleanliness and effectiveness. When the alkalinity is too high, it can lead to hot tub scum, cloudy water, calcium scale buildup, reduced sanitizer effectiveness, and even skin irritation.

Next up, I’ll discuss step-by-step methods on how to lower total alkalinity in your hot tub, allowing you to restore balance and enjoy crystal-clear water once again.

How To Reduce Total Alkalinity In A Hot Tub

To reduce the total alkalinity in your hot tub, there are two effective options I use:

  • The first option is using sodium bisulfate, a dry acid that can be added after testing and measuring the appropriate amount based on your water’s alkalinity level.
  • The second option is using muriatic acid, also known as hydrochloric acid. It should be handled with caution and diluted before adding to the tub.

Both of these chemicals can help maintain a healthy alkalinity level and ensure your hot tub water remains balanced and clear.

Use Sodium Bisulfate

Sodium bisulfate is a dry acid commonly used to lower alkalinity and maintain a healthy pH level. Here are three simple steps for using sodium bisulfate in your hot tub:

  1. Test the water: Before adding any chemicals, test the alkalinity level using a liquid test kit. This will help you determine how much sodium bisulfate you need to add.
  2. Measure the appropriate amount: Once you know the alkalinity level, follow the manufacturer’s instructions to measure the correct amount of sodium bisulfate. It usually comes in a powdered form.
  3. Add and circulate: With the hot tub jets running, slowly pour the measured amount of sodium bisulfate into the water. Let it circulate for at least 30 minutes before retesting the alkalinity level.

Lowering alkalinity with sodium bisulfate is an effective way to balance your hot tub’s chemistry. However, if you’re looking for an alternative method, you can also consider using muriatic acid…

Use Muriatic Acid in a Hot Tub – Lower Alkalinity

Muriatic acid, also known as hydrochloric acid, is a potent tool for lowering alkalinity in your hot tub. However, it is a strong acid and should be handled with care and diluted before adding it to the tub.

As usual, start by testing the alkalinity level of your water and measuring the appropriate amount of muriatic acid needed.

Dilute it with water according to the instructions provided. Slowly pour the diluted mixture into your hot tub while the circulation system is running.

Allow the water to circulate for at least an hour before retesting and adjusting accordingly. Don’t skip testing again – you have just added acid to your hot tub!

Adjust Alkalinity or pH Level?

By now you know that alkalinity and pH are Not the same – although they are related. It is important to test and regulate both to keep your water in top condition. I always recommend adjusting the alkalinity first, then testing your pH and adjusting it if needed.

To adjust the alkalinity or pH level in your hot tub, follow these steps:

  1. Test the water: Use a liquid test kit to measure the current alkalinity and pH levels in your hot tub.
  2. Determine the adjustment needed: Based on the test results, determine whether you need to adjust the alkalinity or pH level.
  3. Adjust alkalinity first: If the alkalinity is too high, add a suitable product like sodium bisulfate according to the manufacturer’s instructions. This will help lower the alkalinity level.
  4. Check and adjust pH if necessary: After adjusting the alkalinity, retest the water and check if the pH level needs further adjustment. Use soda ash, baking soda, or aeration to raise or lower it accordingly.

By following these steps, you can effectively manage and maintain proper hot tub alkalinity levels and keep pH levels in line.

Tips to Manage Hot Tub Alkalinity

Here are some extra tips to help keep alkalinity and pH in perfect harmony:

  • Always allow the water to circulate for at least 30 minutes before retesting and adjusting alkalinity levels. This ensures accurate readings and prevents any sudden changes.
  • Invest in a good quality test kit – try a liquid test kit for more precise measurements.
  • Avoid mixing chemicals together as this can create unforeseen reactions that may affect alkalinity levels.
  • Regularly change your spa water to prevent the accumulation of contaminants that could raise alkalinity.
  • Finally, be sure to adjust alkalinity before addressing pH levels to avoid any complications.

By following these simple yet effective tips, you’ll have complete control over your hot tub’s alkalinity and enjoy a consistently refreshing experience every time you take a dip.

Frequently Asked Questions

Can I use vinegar to lower the alkalinity in my hot tub?

No, vinegar cannot be used to lower the alkalinity in your hot tub. Vinegar only lowers the pH level, not the alkalinity.

How often should I change the water in my hot tub to control alkalinity?

To control alkalinity in your hot tub, it is recommended to change the water every 3-4 months. This will help prevent the buildup of pollutants and minerals that can increase alkalinity levels and lead to other issues in your hot tub.

Is it necessary to adjust alkalinity before adjusting the pH level?

Yes, it is necessary to adjust alkalinity before adjusting the pH level in a hot tub. Alkalinity acts as pH’s bodyguard and helps stabilize the pH level. By adjusting alkalinity first, you can ensure that your pH adjustments are effective and long-lasting.

What are the potential side effects of high alkalinity in a hot tub?

High alkalinity in a hot tub can lead to scale buildup, cloudy water, reduced sanitizer effectiveness, irritation, and high pH levels. It’s important to address this issue to maintain a healthy and balanced environment for your hot tub.

Are there any natural methods or products to lower alkalinity in a hot tub?

There are no natural methods to lower alkalinity in a hot tub. However, you can use products like sodium bisulfate or muriatic acid to effectively lower alkalinity and maintain a healthy total alkalinity level.

To Finish Off

Maintaining the alkalinity level in your hot tub is crucial for water quality. If you notice high alkalinity, it can lead to issues like green water and reduced sanitizer effectiveness.

To lower alkalinity, start by adjusting the alkalinity before pH levels. You can use sodium bisulfate or muriatic acid based on the amount of water in your tub. Remember that vinegar only lowers pH, not alkalinity.

Regularly test and circulate the water, avoid mixing chemicals together, and consider changing the spa water periodically. Sodium bisulfate and muriatic acid are effective options to lower alkalinity but handle them with caution according to instructions.

By following these steps, you can maintain a healthy level of alkalinity in your hot tub.

michael keenan author

Author - Michael Keenan

I'm Michael Keenan the owner and creator of the Outdoor Care Guide. I'm a trained horticulturist with over 30 years of experience in pool care, plant care, and landscape care! Seemed like a good idea to share - I think I can make your life easier and save you some time and money!