What is Hot Tub Alkalinity & How Do You Balance It?

man checking hot tub alkalinity and pH using pH text strips

When it comes to hot tubs, your water quality is everything. Beyond simply being clean, your water chemistry has to be meticulously balanced to ensure a safe, enjoyable experience, while protecting your system from unnecessary damage.

Alkalinity is a key component of water chemistry, and it’s important to know how to keep it properly balanced.

In this guide, we’re going to dive into the intricacies of hot tub alkalinity, exploring the role it plays and providing easy-to-follow instructions to adjust your alkalinity levels.

Let’s get started.

What is Hot Tub Alkalinity, and Why is it Important?

Hot tub alkalinity refers to the water’s ability to neutralize acid, directly influencing the fluctuation of your pH levels. Essentially, it acts as a buffer, helping to stabilize the water chemistry and prevent your pH from drastically swinging from one value to another.

This makes it easier to maintain the overall balance of your water and reduces the amount of chemicals you need to add, reducing your treatment times and keeping your water cleaner. It also plays a significant role in a few other elements of your spa, such as:

  • Water clarity: proper alkalinity levels contribute to clear, inviting water, reducing the risk of cloudy or murky water forming.
  • Sanitizer effectiveness: Imbalanced hot tub alkalinity can impact how well your sanitizer works, leaving your spa at risk of bacteria or algae growth.
  • Spa quality: By reducing pH fluctuations, properly balanced alkalinity levels help reduce the risk of scale or corrosion developing throughout your spa.

So, what exactly does balanced alkalinity look like? The ideal range of hot tub alkalinity is between 80 and 120 ppm (parts-per-million).

Test Hot Tub Alkalinity Using Ph Test Strips

Testing and Balancing Hot Tub Alkalinity Levels

With your water chemistry playing such a pivotal role in the health of your hot tub, testing your water on a regular basis is crucial.

We recommend testing your water at least two to three times weekly. This will ensure you catch any slight changes early, allowing you to make minute changes instead of battling significant fluctuations.

Here’s how to test and treat your hot tub water.

What you’ll need:

  • pH test strips or a water test kit
  • Total alkalinity increaser
  • pH decreaser

Step 1: Run Your Jets For 5 Minutes

Before you can test your water, you’ll want to turn on your jets and let the water swirl around your spa. This will ensure any chemicals will be evenly distributed, resulting in a much more accurate test result.

Simply fire up your jets and let them run for a few minutes.

Step 2: Wait for The Water To Calm

After you’re confident your water has been thoroughly mixed, turn off your jets and wait for the water to still.

If the water in your spa is still bubbling and swishing around, your test result will not be very accurate, which could result in over- or under-treating the water when it comes time to add your products.

Step 3: Dip Your Test Strip Into the Water

Once your water is nice and still, you can test your water with your chosen method. Test strips are by far the most popular option, as they provide clear and easy-to-understand results.

Follow the directions on your bottle of test strips, keeping the test strip in the water for the recommended time.

Then, compare the colours on the strip to the ones listed on the side of the bottle to determine your alkalinity and pH levels.

Step 4: Adjust Your Levels

Now that you know what your current levels are, you can determine how to best treat your water.

How to Decrease Alkalinity:

If your hot tub alkalinity is too high, you’ll need to reduce it, lowering it below 120 ppm. High alkalinity can be caused by a number of things, such as:

  • High Total Dissolved Solids (TDS) levels from too many chemicals (Remember, this can be avoided by changing your water every 3-4 months!)
  • Increased levels of organic matter like body oils, detergent, and dead skin cells
  • A highly alkaline water source

Whatever the cause, if your alkalinity levels are above 120, you need to lower them before you can adjust anything else in your spa.

The easiest way to do this is to use your pH decreaser. Because alkalinity and pH are so closely linked, this product is equally effective at managing hot tub alkalinity and pH; you’ll just need to use a higher quantity.

Following the directions on the bottle, carefully measure out the appropriate amount and add it to your hot tub, allowing it to circulate through your system for 30 minutes with the cover off before re-testing.

As you add your treatment product, keep the jets off, while running the filtration system. This ensures the product can still be evenly distributed through the water, without evaporating.

How to Increase Alkalinity:

If, on the other hand, your alkalinity has dipped below 80 ppm, you’ll need to bring it back up using a Total Alkalinity Increaser.

The main culprit of low alkalinity is contaminants being brought into the water each time you head out for a soak. These could include oils and sweat on your body or lingering detergents on your swimsuit.

When it comes to bringing your alkalinity back into its proper range, Total Alkalinity Increaser or Alkalinity Up will be your best friend.

Simply follow the directions on the bottle, carefully measure out the appropriate amount based on the results of your pH test strip, and add it to your spa. Remember, your filtration system should be running, but jets should be left off.

After 20 minutes, re-test to verify the levels have returned to their expected range. If not, repeat the process.

Follow along with this short video:

Step 5: Balance pH

Now that your alkalinity is within range, you can focus on balancing your pH levels! Using the readings from the test you performed after treating your water’s alkalinity, add the appropriate amount of pH increaser or decreaser to bring it between 7.2 and 7.8.

Do not use the initial results from the first test strip, since this was before you added any products to the water,

Each time you add anything to your water (even just more water), your pH levels will change. This makes it imperative that you only treat your water after knowing its current chemistry, after your last round of treatment.

Hot Tub Care Products and Services in Calgary

Whether you’re struggling with the quality of your water or are looking for a team of professionals to step in and maintain your spa, Sun Spa is here to help!

From bi-weekly care to water changes, filter maintenance and hot tub repair, our team of professional hot tub technicians can help take the work out of owning a spa.

Explore our range of services, and contact our team today, and embrace effortless hot tub ownership.

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