Hot Tub pH vs Alkalinity

As a hot tub owner, you’re aware of how important it is to keep the water balanced. Maintaining proper pH and alkalinity doesn’t just keep your family safe; it’s critical for protecting your spa’s surfaces and equipment.

While most spa owners understand the importance of maintaining this balance, few understand why. We’re often asked, “what’s alkalinity vs pH in a hot tub?” Or, “why does pH in my hot tub matter?” Today, we’re going to shed some light on the subject.

What Is Hot Tub pH?

pH is a measurement used to determine how acidic your spa’s water is. Chemically speaking, pH is short for “potential of hydrogen”. When measuring your spa’s pH, you’re actually measuring how many hydrogen ions are in the water. The more hydrogen ions there are in the water, the less acidic the water becomes.

Have you ever been in a pool or hot tub that caused your eyes to burn? This occurs when the water’s pH is too low. Low pH can also lead to corrosion of your hot tub’s equipment.

High pH levels can also have harmful effects. Without enough acidity, the water produces scale. It becomes cloudy and calcium deposits begin to form. These deposits are harmful to the tub’s surfaces and equipment.

Additionally, high pH levels reduce the effectiveness of chlorine or bromine in the water. Since these chemicals are used to kill viruses and bacteria, improper levels could prove harmful to your friends and family.

When measuring your pool or hot tub’s pH, aim for a reading between 7.2 and 7.6.

What Is Hot Tub Alkalinity?

Alkalinity is important because it measures the number of bicarbonates and carbonates in the water. These substances act as a buffer to help neutralize acidity.

In short, it’s a measurement of the water’s ability to slow down changes in pH. Rapid fluctuations in pH, also known as pH bounce, can cause serious damage to your spa.

When measuring your pool or a hot tub’s alkalinity, aim for 80 to 120 parts per million. Imbalanced alkaline levels can lead to erosion of the tub’s surfaces and equipment, mineral build-up, and can cause the water to turn green.

Relationship Between Alkalinity vs pH in Hot Tub

Because alkalinity and pH are so closely related, it’s nearly impossible to adjust one without affecting the other. We’ve established that low alkaline levels lead to pH bounce. This makes it difficult to achieve proper pH levels. Conversely, high alkalinity makes pH resistant to change. As a result, keeping your hot tub’s water balanced is truly a balancing act, often requiring multiple adjustments before landing on the sweet spot.

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