Hot Tub pH Value - One of the Most Important Values

The hot tub pH value is one of the most important measurements for proper hot tub water care. It should always be between 6.8 and 7.2 in a hot tub.

Why Does the Hot Tub pH Value Need to Be Correct?

The hot tub pH value is crucial in pool water for the effectiveness of disinfectants, the comfort of bathers (skin and eye compatibility), and protecting pool materials from corrosion or deposits. The optimal pH value lies within a narrow range between 6.8 and 7.2 (a value of 7.0 is often considered ideal
).

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Why Is the Hot Tub pH Value So Important for Hot Tub Water Care?

Optimal Disinfection: Chlorine, the most commonly used disinfectant, only works efficiently within this optimal pH range. If the pH value rises above 7.4, the effectiveness of chlorine decreases rapidly, which can lead to inadequate hygiene and algae growth. The same applies to other disinfectants used for hot tub water care.
Skin and Eye Compatibility: A correctly adjusted pH value (close to the natural pH value of human tears and skin) prevents skin and eye irritation for bathers.
Protection of the Pool System: If the water is too acidic (pH value below 6.5), it can cause corrosion to metal and plastic parts. If it is too alkaline (pH value above 7.6), limescale deposits can form.

Clear Water: A balanced pH value contributes to the clarity of the pool water. Incorrect values can cause cloudiness. From 7.4 onward, the water already develops a slight bluish tint, and from 7.6 onward, the water begins to turn milky. This cannot be filtered because it is discoloration, not contamination. Even the best
hot tub filter cannot change this.

Regularly checking and adjusting the pH value is therefore the foundation for effective hot tub water care and safe, clean bathing enjoyment.

And now for the EGo3 Hot Tub Guru tip, because this is the most common mistake when adjusting the pH value!

MOST TESTING PRODUCTS MEASURE THE PH VALUE IN A HOT TUB INCORRECTLY.

Why is that? Almost all testing products were originally developed for pools and not for hot tubs. And there is one crucial difference between these two products when it comes to hot tub water care - ALKALINITY.

In pools, it is approximately stable, while in hot tubs it is almost always too low. However, alkalinity that is too low distorts the pH measurement result: the reading is 0.1 too low for every 10 below the correct alkalinity of 120. So, you measure a hot tub pH value of 7.2 with test strips, but the alkalinity is only 40. Your actual pH value is then 8.0, which is completely outside the correct range. Disinfectants barely work anymore, and the water turns green and cloudy. The water also becomes milky, even though the pH value according to the test strips is correct. More disinfectant is added, the hot tub filter has to run for many more hours, and it still does not help.

FORMULA FOR CORRECT PH VALUE CALCULATION

Correct pH value = measured pH value plus 0.1 for every 10 points of TA below 120!

Why don't the manufacturers of testing products change this? Because measuring correctly is more expensive and more complicated, and it does not matter for the vast majority of customers (those with swimming pools).

Why isn't this explained when the hot tub is delivered and during hot tub water care training? Because you have to buy much more chemicals and hot tub filters if you do not know this, and probably also due to the hot tub dealer's sheer lack of knowledge.

What do I have to do? Either use a testing product such as Pool Lab that takes the deviation into account, or calculate it using the formula above to achieve perfect and correct hot tub water care.

INSIDER PH VALUE TIP: If the water is milky, the pH value is ALWAYS too high. You are simply using the wrong testing product, which does not measure the hot tub pH value correctly for optimal hot tub water care