PoolDose, the pool chemical calculator for iPhone and iPad
Chemical Calculator & Test Log
PoolDose turns a test strip reading into an amount of product: millilitres or grams for the chlorine, acid, alkalinity booster or salt you actually have, for the volume of your pool. It also works out the pool volume, checks whether the water will corrode or scale, and keeps a log. It is free to download, has no ads and needs no account.
On a computer? Scan with your phone camera to install.
Version 1.0.0 Updated 2026-10-09Requires iOS 17.0Size 2 MBPrice Free For iPhone and iPad
What can you do with it?
- Under the Calculator tab: Volume for rectangular, oval, round, kidney and stepped-bottom pools, with an optional Sloped bottom; Dosing for nine products; Water Index for the Langelier Saturation Index; and Assistant, which lists what to fix in order.
- Dosing covers Chlorine, pH down, pH up, Alkalinity, Calcium hardness, Stabilizer (CYA), Salt (salt chlorinator), Flocculant and Algaecide.
- Under the Log tab: pool readings by date, two 90-day charts (free chlorine and pH), Scan test strip to fill a reading from a photo, and Export CSV and Export PDF.
- The Guide tab holds the correction order and a short safety list. Settings has the metric or US switch and the reminders.
Quick start: your first chlorine dose
- Open Calculator > Volume, pick your Shape, type the measurements and tap Use this volume.
- Go back and open Dosing. Chlorine is already selected.
- Under Chlorine source, choose what is in your shed, for example Liquid sodium hypochlorite, 15%.
- Type what the strip says in Measured (ppm) and where you want to be in Target (ppm).
- Read the amount under Dose. For a 50 m³ pool going from 0 to 1 ppm with 15% liquid chlorine, that is 333 ml.
What is free
Everything in this version: all calculators, the log, the charts, the reminders and the export. There are no ads, no account and no in-app purchases. The app shows no paywall or upsell, and we make no promises about future versions.
Offline, camera and notifications
Every calculation runs on the phone, so a pump room with no signal is fine. Readings stay on the device, with no sync and no sign-up. The camera and photo library are only asked for when you use Scan test strip, and notifications only if you turn on Weekly + seasonal reminders.
Limits you should know about
- The doses are flat trade rates, not a titration. They do not see your alkalinity when you lower pH, for example.
- There is no dose for lowering alkalinity, calcium hardness or stabilizer. Those need dilution.
- The strip reader picks the nearest of six reference colours per pad and is not calibrated to any strip brand.
- No hot tub mode, no shock mode, no iCloud sync, no Apple Watch app.
How-to guides for PoolDose
How much chlorine to add to a poolMultiply the ppm you want to add by the pool volume in cubic metres and you have the grams of active chlorine, then divide by the strength…How to calculate pool volume in gallons or litresArea times average depth gives the volume. A rectangle 8 m by 4 m at 1.5 m deep holds 48 m³, which is 48,000 litres. The Volume screen…How much acid to lower pool pHIn PoolDose a drop of 0.1 pH costs 15 g of sodium bisulfate (dry acid) or 10 ml of 33% hydrochloric acid per cubic metre. Taking a 50 m³…Pool LSI calculator: is your water aggressive or scaling?The Langelier Saturation Index adds up pH, temperature, calcium hardness and alkalinity (corrected for stabilizer) and subtracts a…What order to balance pool chemicalsAlkalinity first, pH second, chlorine third, stabilizer last. PoolDose's Assistant applies that order to your readings, shows the dose for…How much salt to add to a salt water poolEach g/l you need to add takes 1 kg of salt per cubic metre of water. Taking a 50 m³ pool from 1.5 to 4.5 g/l is 150 kg. The Salt (salt…A pool water test log, with a test strip scannerThe Log tab stores each reading against a pool, charts free chlorine and pH for 90 days against a shaded target band, and exports to CSV or…
Questions people ask about PoolDose
Is PoolDose free?
Yes. All of it is free to download and use: calculators, log, charts, reminders and export. There are no ads, no account and no purchases in this version.
Does it need internet?
No. The maths runs on the iPhone or iPad. The app makes no network calls of its own, so it works beside the pump with no signal.
Which chlorine can I choose?
Liquid sodium hypochlorite at 15% or 10%, calcium hypochlorite 65-70%, trichlor 90% and dichlor 56%. Liquids come out in millilitres, solids in grams.
Does it work for a salt water pool?
Yes for the dosing, including a Salt (salt chlorinator) product. The Langelier index is only an approximation there, because it assumes a fixed dissolved solids figure.
Can I use US units?
Yes. In Settings > Units you can switch from metric to US (feet, gallons, °F, ounces and fluid ounces). It defaults to your device region.
Can I trust the numbers blindly?
No. The Dosing screen tells you its numbers are orientative. Use the product label first, add part of the dose, let it circulate and test again.
Privacy and support
PoolDose works offline and does not require an account. Read the privacy policy and the terms for this app, or write to us if something is wrong.
