When it comes to keeping your hot tub water clean, clear, and comfortable, balancing the chemistry is crucial. While most hot tub owners are familiar with testing and adjusting pH levels, alkalinity often doesn’t get the attention it deserves. It plays a vital role in your water’s overall balance, and maintaining the right level is essential for protecting both your hot tub and your skin. In this blog post, we’ll explore what alkalinity is, why it’s important, and how to keep it at the optimal level in your hot tub.

What is Alkalinity in Hot Tub Water?

Alkalinity refers to the water’s ability to resist changes in pH, or its “buffering capacity.” In simpler terms, it acts as a stabilizer that helps prevent the pH levels from fluctuating too much. When it is not properly balanced, the pH levels in your hot tub can swing drastically, which could lead to discomfort, skin irritation, and damage to your hot tub’s surfaces and equipment.

While alkalinity and pH are related, they are not the same. Alkalinity is essentially the precursor to pH stability. When it is out of balance, it becomes much harder to adjust and maintain your pH within the ideal range.

Why Does It Matter?

1. 1. Prevents pH Fluctuations: If alkalinity is too low, pH levels can easily spike or drop, leading to acidic or alkaline water. This can cause skin irritation, eye discomfort, and corrosion of metal parts within the hot tub. On the other hand, if it is too high, the pH can become difficult to lower, leading to cloudy water and scaling.

1. 1. Protects Your Equipment: Proper alkalinity helps protect your hot tub’s internal equipment, including heaters, pumps, and jets. Unstable pH levels can cause corrosion or scaling, leading to costly repairs and a shorter lifespan for your tub.

1. 1. Improves Comfort: Maintaining balanced alkalinity helps ensure that the water in your hot tub feels comfortable and soothing. If the water is too acidic or too alkaline, it may irritate your skin and eyes, turning your relaxing soak into an unpleasant experience.

1. 1. Optimizes Chemical Effectiveness: Proper alkalinity also enhances the effectiveness of other chemicals used to treat your hot tub, such as sanitizers (chlorine or bromine) and shock treatments. When it is off, it can interfere with these chemicals, making it harder to maintain clear and clean water.

Ideal Alkalinity Levels for a Hot Tub

The ideal range for alkalinity in your hot tub is 80 to 120 parts per million (ppm). Maintaining proper water balance ensures that your water is stable, comfortable, and safe for soaking.

• • Low Alkalinity (<80 ppm): Low alkalinity can cause the pH to fluctuate, leading to acidic water. This can result in skin irritation, corrosion of hot tub equipment, and damage to surfaces. It can also make the water feel uncomfortable and may interfere with other chemicals.

• • High Alkalinity (>120 ppm): High alkalinity can lead to a high pH, causing the water to become overly alkaline. This can result in cloudy water, scaling on the tub’s surfaces and equipment, and reduced sanitizer efficiency. It can also make it difficult to adjust the pH to the desired range.

How to Test Alkalinity in Your Hot Tub

Testing your hot tub’s alkalinity is simple and can be done with a test kit or test strips, both of which are readily available at pool and spa stores. Here’s how to do it:

1. Collect a Water Sample: Take a sample of water about 6 inches below the surface of your hot tub. 
2. Use the Test Kit or Strips: Follow the instructions provided with your test kit or strips. Usually, you’ll add a few drops of a reagent solution to the water sample, or you’ll dip the strip into the water and compare the results to the color chart provided.
3. Record the Results: Once you’ve tested the water, note the reading. If it falls outside the ideal range, you will need to adjust it.

How to Adjust Alkalinity in Your Hot Tub

If your alkalinity is too high or too low, you can adjust it using specialized chemicals. Here’s how to bring your alkalinity levels back into the ideal range:

1. To Increase Alkalinity:

If the level is too low (below 80 ppm), you can raise it by adding an increaser (also called sodium bicarbonate or baking soda). Here’s how:

• • Calculate the Amount Needed: Check the instructions on the product label to determine how much to add based on your hot tub’s water volume.

• • Add the Chemical: Slowly pour the increaser into the water while the hot tub’s jets are running to help distribute it evenly.

• • Retest the Water: After adding the increaser, wait for a few hours and retest the water to ensure the level has reached the ideal range.

2. To Decrease Alkalinity:

If the alkalinity is too high (above 120 ppm), you can lower it by using a pH decreaser. Here’s how:

• • Dilute the Acid: Always dilute the acid with water before adding it to your hot tub. Follow the manufacturer’s instructions carefully to avoid adding too much.

• • Add the Acid: Slowly add the diluted acid to the hot tub while the jets are running to help mix it thoroughly.

• • Retest the Water: After adding the acid, retest the water in a few hours to ensure that it is within the recommended range.

Tips for Maintaining Proper Alkalinity

• • Test Weekly: Since alkalinity can fluctuate, it’s important to test your hot tub water regularly, ideally once a week, to catch any imbalances early.

• • Use a Cover: Using a cover when your hot tub is not in use helps prevent debris and contaminants from entering the water, making it easier to maintain proper alkalinity.

Conclusion

Maintaining proper alkalinity in your hot tub is essential for ensuring that your water is balanced, safe, and comfortable. With the right alkalinity levels, you’ll avoid pH fluctuations, protect your equipment, and enhance your overall spa experience. Regular testing and adjustments are key to achieving a healthy and enjoyable hot tub, so don’t overlook this vital aspect of water chemistry.

By keeping your alkalinity in check, you’ll extend the lifespan of your hot tub, reduce maintenance costs, and enjoy countless hours of soothing, worry-free relaxation.

Have more questions about your hot tub’s water balance? Visit us in store for even more expert advice!