A too high pH level may cause you uncomfortably when you use the hot tub water, which backfires on the hot tub bathers who want to relax and unwind.

Chemical pH decreasers can be the solution for this problem, but our article will suggest to you how to lower pH in hot tub naturally with a product already available in your kitchen.


What is hot tub pH?

There are three basics in hot tub chemistry including alkalinity, pH, and calcium hardness.

The first two basics alkalinity and pH go hand in hand. The total alkalinity is the water’s ability to neutralize acids. It acts as a buffer to reduce the level of acidity in your hot tub water. The aim of alkalinity for your hot tub should be between 125 and 150 parts per million.

On the other hand, pH measures whether a solution is basic or acidic. The pH scale ranges from 0 to 14 with 7 being neutral. The lower the pH is equivalent to the more acidic water.  On the contrary, the higher the number the more basic the solution is.

You may try to achieve a pH level between 7.4 and 7.6 with 7.5 being the most ideal level.

In other words, when a solution has more hydrogen ions than plain water, it’s acidic, while the contrary means it’s basic. When using test strips or a kit to test liquid, you will know how acidic or basic your hot tub water is.

Why does a balanced pH matter?

hot tub ph

A pH level that is lower than 7.4 is potentially dangerous. The lower pH level indicates more acidic hot tub water.

Since highly acidic water reduces the effectiveness of your sanitizer, bathers in your hot tub are exposed to potentially harmful contaminants. This raises their risk of contracting bacteria such as pseudomonas aeruginosa causing hot tub folliculitis or legionella causing Legionnaires’ Disease, and so on.

In addition, a low pH hot tub water may corrode spa components, the replacement of which can be costly.

By contrast, any hot tub water with a pH level that is higher than 7.6 can be considered basic. Basic water is equivalent to be poorly sanitized and poses the same risks as other causes of ineffective sanitization.

For these reasons, it’s essential to maintain your hot tub water ideally between 7.4 and 7.6. In a less stringent manner, a pH level from 7.2 and 7.8 is already acceptable.

The rule of thumb is when your hot tub water is acidic (equivalent to a low pH level), you’ll add alkaline chemicals to raise the pH level. On the contrary, when your hot tub water is basic (equivalent to a high pH level), you’ll add acids to reduce the pH level.

Signs of unbalanced pH

Either too high or too low pH levels reduce the effectiveness of chlorine-based disinfectants. Consequently, the water quality degrades, which causes build-up and other issues in your hot tub.

High pH and alkalinity levels will lead to the formation of flake scales which are partly caused by high calcium hardness. Other signs of basic water are cloudy water, skin and eye irritation. Your hot tub’s filter will also reduce its lifespan.

On the contrary, too low pH and alkalinity will result in corrosion, etched or stained plaster.

If your hot tub has one of these signs, its pH level is likely to be unbalanced.

How to lower pH in hot tub naturally?

To lower pH, you can use products available in most stores for pH regulation. If there are none available in your local stores, you can use vinegar or apple cider vinegar as alternatives.

Vinegar is a weak acid that can reduce the pH level of your hot tub water. In addition, many people also use vinegar to clean their hot tub filters.

So how to lower pH in hot tub with vinegar?

lower pH in hot tub with vinegar

The following are the steps to lower pH in the hot tub naturally with the help of vinegar.

  • Step 1: Let the water circulate for a few hours. Then test the pH of the hot tub water. The ideal read should be from 7.2 to 7.6.
  • Step 2: Reduce the pH level of the water by adding 4 cups of vinegar. Next, pour them directly into the hot tub water. Either white vinegar or apple vinegar can work.
  • Step 3: Make sure the pump is running after you add the vinegar because you would want the weak acid to properly circulate throughout the hot tub.
  • Step 4: Allow the pool pump to run for several hours to help the water recalibrate. Test again with the test strips.
  • Step 5: If the pH read in step 4 still hasn’t reached the ideal level, repeat steps 2 to 4 until it reaches between 7.2 to 7.6.

Precautions when using Muriatic acid

Muriatic acid is also one of the commonly-used pH decreasers, but you should be careful when using this chemical.

Muriatic acid is extremely caustic, so you must use protective gear including safety glasses, chemical-resistant gloves, and a cautious attitude when choosing this pH decreaser.

You can replace muriatic acid with its non-caustic replacement product. However, safety gear is still needed.

Pouring muriatic acid directly into your hot tub water is not a good idea. You’ll first need to dilute it, then add it to the hot tub water and aerate it with the jets. The final step is to retest the water after allowing it to circulate overnight.

Bottom line

The pH level plays an important role in guaranteeing you the best experience when you use the hot tub. When seeing signs of too high pH, you should recalibrate it.

The answer to how to decrease pH in hot tubs can be as simple as vinegar and apple cider vinegar. We have already included step-by-step instructions so you can follow them at home to solve your hot tub’s acidic problem.


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