CliniPool / Understand your water
Total alkalinity (TA): the silent guardian of your pH
- Total alkalinity (TA) measures the water's buffering power — its ability to stabilise the pH.
- Usual ideal range: around 80 to 120 ppm (mg/L).
- TA too low = unstable pH, jumping at the slightest addition (yo-yo effect).
- TA too high = pH 'stuck' high and hard to lower; you ALWAYS set the TA before the pH.
Total alkalinity (TA) — sometimes called the “buffer” — is the most discreet and one of the most important parameters of your pool. It measures the water’s buffering power: its ability to absorb product additions without the pH going haywire. It’s the guardian of the pH. Ideal range: around 80 to 120 ppm. Too low, the pH becomes unstable and yo-yos at the slightest event; too high, it sticks up high and resists every correction. The golden rule that follows: you set the alkalinity before the pH, never the other way round. The CliniPool app always looks at the pH/TA pair together and calculates corrections in the right order.
What alkalinity really does
Picture the pH as a ball, and the alkalinity as the firmness of the ground under that ball. Correct TA: the ground is stable, the ball (the pH) stays where you put it. TA too low: the ground is soft, the ball rolls everywhere — every rain, every swim, every product addition shifts the pH abruptly. TA too high: the ground slopes steeply upward, the ball always rolls back up and refuses to come down — that’s the pH “stuck” at 7.8 you just can’t bring down.
That’s why so many people “chase the pH” without ever stabilising it: they correct the symptom (the pH) while ignoring the foundation (the alkalinity).
Why alkalinity drifts
Alkalinity moves more slowly than the pH, but it moves. pH correctors influence it (pH− also lowers the TA). Top-up water matters enormously: depending on your region, tap water can be very alkaline or very soft, and every refill shifts the TA. Rain, soft and slightly acidic, pulls it down. And certain sanitisers have an effect depending on their nature. The takeaway: alkalinity is measured regularly (a few times a season is enough, it’s slow), especially after big water top-ups.
Setting it, in the right order
To raise the alkalinity, you use an alkalinity increaser (bicarbonate). To lower it, you use a pH corrector at an adapted dose, in stages. The subtlety: correcting the alkalinity temporarily shifts the pH, so the operation calls for a light touch and re-tests — exactly the kind of cascading calculation the app handles, telling you what to adjust, in what order, and when to re-test.
Once the alkalinity is in range, the reward is immediate: the pH settles on its own and your corrections hold over time, instead of replaying every three days.
In one sentence
Alkalinity can’t be seen or felt, but it commands the stability of everything else. Measure it, keep it in range, and your pH stops being a constant worry. The app tracks the pH/TA pair at every test and warns you when the foundation shifts — before the pH spins out.
Frequently asked questions
Should you set the alkalinity or the pH first?
Alkalinity first, always. It's what stabilises the pH: a TA in range makes pH corrections last, whereas an off-range TA turns the pH into a moving target no matter what product you use.
What's the right alkalinity value for a pool?
The usual ballpark sits between 80 and 120 ppm (mg/L of CaCO₃). Below that, the pH becomes unstable; above it, it tends to stay stuck high. The app sets the exact target to your pool type and sanitiser.
Why does my pH keep moving?
Almost always because of a TA that's too low: without enough buffering power, the slightest rain, swim or correction sends the pH jumping. Bringing the TA into range stabilises the pH for good.
Alkalinity and pH, what's the difference?
pH measures the water's instant acidity; alkalinity measures its resistance to pH change. Alkalinity isn't directly 'felt', but it decides whether your pH holds or spins out of control.