Test Entry
Enter free chlorine, combined chlorine, pH, total alkalinity, calcium hardness, CYA, salt, borates and temperature in US units (gallons, °F) or metric (litres, °C). Leave out any reading you did not take.
Pool & Spa Water Chemistry
Chlorly the products you own.
Chlorly: Pool Water Calculator (decided 2026-10-05). C# .NET 10 MAUI, iPhone + Android, fully offline, no server. Pools/spas with a volume calculator (rectangle, round, oval, kidney, freeform average depth; gallons or litres), surface (plaster/vinyl/fibreglass) and sanitiser (liquid chlorine, trichlor tabs, cal-hypo, dichlor, salt water generator, bromine for spas). Manual test entry: FC, CC, pH, TA, CH, CYA, salt, temperature, borates; US or metric units. Targets: FC tied to CYA (FC/CYA ratio method incl. SLAM shock level), pH 7.2-7.8, TA by sanitiser, CH by surface, salt for SWG; status colours + plain-English explanations. Dosing: exactly how much of WHICH product the user owns (liquid chlorine 6-12.5%, muriatic acid 31.45%/14.5%, dry acid, baking soda, soda ash, calcium chloride, CYA stabiliser, salt, borax) with order of addition, wait times and a never-mix warning. CSI saturation index. Test log + charts, next-test reminders (local notifications), maintenance log. Free: 1 body of water, dosing, last 10 tests, AdMob banner on log/history/settings (never on the dosing result card). Pro $7.99 once (com.bekservice.chlorly.pro): unlimited pools/spas, full history + charts, CSI, reminders, CSV/PDF export, no ads. Every formula unit-tested against documented reference values. No health claims; always follow product labels.
What it does
Targets Tied to Your CYA
Free chlorine targets follow your CYA level using the FC/CYA method, including the SLAM shock level. pH, alkalinity, calcium and salt targets adjust to your sanitiser type and pool surface. Every reading gets a colour and a plain-English explanation.
Doses for Your Products
Tell Chlorly which products are on your shelf and the strength on each label. It calculates how much of which product to add — in fl oz, gallons, pounds, millilitres or grams — with a safe order of addition, wait times between steps and a reminder never to mix chemicals.
Pool Volume Calculator
Rectangle, round, oval, kidney and freeform shapes, each with separate shallow and deep end depths. Or type your volume directly. Gallons or litres.
Accurate Chemistry Model
pH corrections use an acid/base equilibrium model that accounts for alkalinity, CYA and borates — not a lookup table. The saturation index (CSI) shows whether your water is etching plaster or depositing scale. Every formula is unit-tested against published reference values.
Log, Charts and Reminders
Every test is saved and plotted over time against its target band. Log filter cleans, backwashes and shocks. Get a local notification when your next test is due.
A look inside
Start free. Upgrade once.
Free
One pool or spa. Full test entry, dosing plan and volume calculator. The last 10 tests saved. Maintenance log. A small banner advert on the log, history and settings screens — never on the dosing result card.
Chlorly Pro — one payment, no subscription
Unlimited pools and spas. Full test history with charts. Saturation index (CSI). Test reminders. CSV and PDF water reports. No adverts. One payment of $7.99, no recurring charge.
Private by Design
Your tests stay on your phone. No account to create, no data sent to a server. The only third-party code is Google AdMob for the free version's banner, shown after you choose your consent.