Is Total Alkalinity (TA) the Hidden Cause of Your Pool Problems?

Understanding Total Alkalinity (TA) in Pools and Spas

Total Alkalinity (TA) is a vital part of maintaining safe and balanced water chemistry.

Although TA is sometimes considered less important than pH or chlorine levels, it plays a crucial role in controlling both. For this reason, TA should be regularly tested and managed to ensure safe and comfortable bathing conditions for all users.

Why is TA important?

Low TA has always been a common issue in spa pools, where air introduced through blowers and jets can gradually reduce alkalinity.

However, a growing trend—particularly in the southeast—is seeing low TA readings in swimming pools that previously haven't required regular monitoring or management of their alkalinity levels.

What should you look out for?

Are you finding that you're overdosing on pH correction chemicals? Are your chlorine readings suddenly spiking?

These can be signs of low TA and may indicate a phenomenon known as pH bounce.

When TA is low, potentially anywhere from below 50 ppm, the water has insufficient buffering capacity to stabilise the pH. This means that even relatively small additions of acid can cause significant fluctuations in pH.

As a result, the pH and chlorine levels can appear to fluctuate or "bounce" up and down. Because chlorine is more effective at lower pH levels, changes in pH can also affect the measured and effective strength of the chlorine in the water.

In short, when alkalinity is too low, the water becomes much more difficult to control, resulting in repeated adjustments to both pH and chlorine.

How can it be corrected?

If this sounds familiar, don't worry—the pool or spa can quickly return to normal operation once the underlying issue is addressed.

The first step is to increase the Total Alkalinity to around 140 ppm using TA+.

Always follow the product label and recommended safe-handling procedures when adding TA+.

If your pool or spa has an automatic dosing system, remember to close or isolate the automatic dosing sample valves for at least one hour. This allows the TA+ to circulate through the system without interfering with the controller's sensors and causing unnecessary chemical dosing.

Once the TA has been restored to the correct level, the water chemistry should become significantly more stable, making pH and chlorine levels easier to maintain.

Sound familiar?

If you're experiencing unexplained pH fluctuations, inconsistent chlorine readings or repeated chemical overdosing, low TA could be the missing piece of the puzzle.

Have questions or need some advice? Get in touch — we're happy to help.