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Having a spa or hot tub is really nice. When you want to soak after a long day or warm up in the colder months. Whenever is good for you to take advantage of the spa, you want to make sure that the alkalinity is not too high. Wondering how to lower alkalinity in a spa? There are a few methods you can do such as use a pH decreaser or dilute the water with fresh water.

What Is Alkalinity?

Alkalinity refers to the measure of how much alkaline compounds are present in your hot tub’s water. It is an important factor to maintain the overall balance and stability of the water chemistry.

High alkalinity spa needs to be lowered.

What Causes High Alkalinity?

High alkalinity in a hot tub can be caused by various factors such as the use of hard water, adding excessive chemicals like baking soda, or even due to the accumulation of debris and organic matter over time.

If alkalinity levels get too high in a hot tub, it can lead to several problems. It can cause a pH imbalance, which makes it difficult for sanitizers to work effectively, resulting in cloudy water and potential health risks. Additionally, high alkalinity can also lead to scale formation on the surfaces of the hot tub and its equipment.

Emptying spa to lower alkalinity.

If The Alkalinity Is High, How Do You Lower It?

To lower alkalinity in a hot tub or spa, you can try a few methods. One option is to use a pH decreaser or acidifier product, such as muriatic acid, to bring down both pH and alkalinity. Another method is to dilute the water with fresh water, although this may require draining and refilling the hot tub entirely.

Balancing and Controlling Alkalinity

When adjusting pH and alkalinity, it is generally recommended to first focus on balancing alkalinity before adjusting pH levels. This is because alkalinity acts as a buffer and helps stabilize the pH level.

Here are some tips to help you control alkalinity in your hot tub:

  1. Regularly test the water using a reliable test kit to monitor alkalinity levels.
  2. If needed, use appropriate products to adjust alkalinity and pH levels.
  3. Keep the hot tub clean by regularly removing debris and maintaining proper filtration.
  4. Avoid using hard water in your hot tub, as it can contribute to higher alkalinity levels.
  5. Follow manufacturer guidelines and recommendations for chemical usage and water maintenance.

Other Recommended Maintenance

Now that you know about alkalinity in the spa, there are a few other areas of recommended maintenance to think about. One of those is about a draining spa. Your spa can drain due to a failed check valve, actuator valve, air leak, or diverter.

Another area is mold on the pool deck. If you have a pool, sometimes you may see mold on it. This Is because of mold spores that settle on the deck. To get rid of it, you can use a scrub brush, bleach, water, a pressure washer, and a vacuum.

When Do I Call A Professional?

If you find it challenging to maintain proper alkalinity levels or experience persistent issues, it might be best to seek professional assistance. You will want to contact a hot tub specialist or water chemistry expert. They can provide proper guidance and help you resolve any underlying problems effectively.


In conclusion, maintaining the right alkalinity levels in your hot tub is crucial for water balance and overall system performance. By being proactive and following proper maintenance practices, you can enjoy clean and healthy water in your hot tub. Reach out to RedFish Inspections Home Inspection services for a full spa inspection and home inspection in Houston, TX, and the surrounding areas.

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