Guides
Seven guides that go deeper than a single calculator: the order to work in when lowering pH or raising alkalinity, which chemicals never to combine, what cyanuric acid is actually doing in the water, a green pool's first steps, opening and closing a pool each season, and how to read an EPA-registered product label.
Fixing a problem
A Green Pool: What to Do FirstThe order for bringing a green or cloudy pool back — test, brush, shock, filter continuously, retest — before reaching for an algaecide.
How to Lower pH in a Pool: the Order, Not a DoseThe sequence for lowering pool pH safely — alkalinity first, small doses of acid, retest — and why this site prints no acid dose for a pH move.
How to Raise Alkalinity in a PoolThe order for raising total alkalinity with baking soda or soda ash, why it comes before pH, and where the pH and alkalinity calculator picks up the dose.
Knowing your chemicals
Never Mix These Pool ChemicalsWhy pool chemicals that look like ordinary powders and liquids can react violently together, with real incidents from EPA's own safety alert.
Reading a Pool Chemical LabelHow to find the active-ingredient percentage, the signal word and the re-entry limit on an EPA-registered pool chemical label, using this site's saved labels.
What Cyanuric Acid Does in a PoolHow cyanuric acid stabilizes chlorine against sunlight, why it isn't free, and what the 45:1 ratio and the 90 ppm ceiling are protecting against.
