A plain-language reference for every pool chemistry term. What each one means, what range to aim for, and why it matters. No jargon, no fluff.
The active chlorine in your water — what actually sanitizes. Target depends on your CYA level.
Spent chlorine bound to organics — the source of "pool smell," eye irritation, and the signal that your FC is losing the chemistry race.
Free chlorine plus combined chlorine. The reading that misleads on its own — only useful when paired with FC.
The compounds responsible for "chlorine smell" and eye irritation — and why the fix is more chlorine, not less.
The shock level that destroys chloramines and resets your chlorine — and the CYA-based target that determines exactly how high FC needs to go.
A direct measure of sanitizing strength, used widely in EU and pro systems.
Coming soonHow acidic or alkaline your water is. The reading that controls chlorine effectiveness — high pH wastes most of the chlorine you add.
The buffer that keeps pH stable. Too low and pH swings wildly; too high and pH drifts upward no matter how much acid you add.
The biggest single lever for LSI. Too low = corrosive water attacking plaster and metal. Too high = scale on tile, heaters, and salt cells.
The water balance number that ties pH, TA, CH, and temp together — and why most calculators get it wrong.
The chloride that lets a salt water generator make chlorine.
Coming soonEverything dissolved in your water — minerals, salts, chemicals.
Coming soonAlgae food — but not the cause of green pools. What phosphates actually do and when they matter.
Optional additive that buffers pH and inhibits algae growth.
Coming soon
