Why your chlorine won't hold
You keep adding chlorine and it keeps disappearing. It is almost never the chlorine. Here is what is actually going on.
The assumption we're testing
“Just add more chlorine”
Chlorine needs the water to be right first
Chlorine only works properly within a fairly narrow pH range. Drift too high and the chlorine is still in the water but barely doing anything. You can dose and dose and get nowhere.
That is why a pool can test as having chlorine and still go cloudy. The chlorine is there. It just cannot work.
So the first thing to check is never the chlorine. It is the pH and the alkalinity underneath it.
The stabiliser trap
Stabiliser protects chlorine from the sun. Without it, a Sydney summer burns off most of your chlorine in a day.
But stabiliser does not leave the water the way chlorine does. It builds up. Once there is too much, it starts locking the chlorine up instead of protecting it — and the only real fix is diluting the water.
This is the single most common reason we get called to a pool that has had plenty of chlorine tipped into it and is still green.
What a proper test shows
A strip test tells you chlorine and pH and not much else. The things that actually decide whether your pool behaves — alkalinity, calcium, stabiliser, salt — need a proper test.
We do that on every visit and write the numbers down, so you can see what changed since last time rather than guessing.
This is Water testing & balancing territory.
See the brigade