Why this exists
Most pool calculators are a pile of disconnected single-number tools that hand you a result with no plan — and several of them quietly get the chemistry wrong. Pool Chem Lab does it the way a working tech does: it looks at your whole pool at once, doses in the right order, and gets the two things most calculators fumble — CYA-corrected water balance and CYA-scaled chlorine — right.
Who's behind it
The tools, dosing math, and target ranges come from a real recurring-route pool-service operation and the Pool Service Mastery curriculum — not scraped from a forum. Target ranges follow CDC Model Aquatic Health Code, PHTA, and Taylor Technologies guidance.
How we calculate
CYA-corrected LSI
Cyanuric acid shows up in a total-alkalinity test but doesn't buffer against scale, so we subtract the cyanurate portion to use true carbonate alkalinity. That keeps your saturation index honest instead of falsely optimistic.
CYA-scaled chlorine
Free chlorine has to scale with CYA — a flat "1–3 ppm" is why stabilized pools still go green. We target about 7.5% of your CYA, and base shock levels on CYA too.
Dose in the right order
Alkalinity, then pH, then calcium, then CYA, then chlorine — with re-test gates, because adjusting one parameter moves the others.
An honest note on precision
Doses are accurate starting estimates for your volume and chemical strength. Pool chemistry has real-world variability, so always add a little less than the maximum, let it circulate, re-test, and confirm against your product's label. These tools are educational and don't replace a water test or professional advice.