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iOS · Private on-device

Stop guessing gallons of bleach

FC, CYA, dose. That's the job. Pool Bible turns your FC and CYA test into an exact liquid-chlorine dose — then helps with LSI balance, trends, and reminders when you want more.

Download on the App Store

Roughly 5% of what pro chemistry apps teach — 100% of what most owners need between swim weekends.

Backyard pool with liquid chlorine and test kit on the deck

Sample dose

48 fl oz

12.5% liquid chlorine

Free chlorine
1.0 ppm
CYA
50 ppm
Target
6 ppm FC
Pool
18,000 gal

Built for backyard pools

Pro calculators bury you in phosphates and SKUs. Pool Bible starts where water actually breaks: chlorine, stabilizer, and the dose.

Sparkling residential backyard swimming pool

  • Exact bleach dose

    FC and CYA in, ounces or gallons out — sized to your pool volume and bleach strength.

  • LSI when you're ready

    Full Langelier balance with fix order when you log pH, alkalinity, and calcium.

  • Scan, don't type

    Photo your test log or bleach label. On-device OCR fills readings for you.

  • Trends & reminders

    Charts with target bands, CSV export, and weekly test notifications.

  • 11 pool shapes

    Volume estimator for rectangle, kidney, L-shaped, freeform, and more.

  • Private by design

    All pool data stays on your iPhone. No account required.

Two numbers in. One dose out.

  1. Backyard pool ready for volume setup

    Add your pool

    Name and gallons — use the built-in volume estimator if you're not sure.

  2. Testing pool water with strips and kit

    Log FC & CYA

    Type results or scan a photo from your test strip or Taylor kit.

  3. Pouring liquid chlorine into a residential pool

    Pour with confidence

    Daily target or shock level, with plain-English guidance — not a SKU catalog.

Frequently asked questions

Is Pool Bible a substitute for professional water testing?
No. Pool Bible is a homeowner helper for dosing and logging. Always follow product label instructions and use a reliable test kit.
Does Pool Bible require an account?
No. Your pool data stays on your iPhone. There is no cloud account for core features.
What test results do I need for a bleach dose?
Free chlorine (FC) and cyanuric acid (CYA) are enough for your first dose. pH, alkalinity, and calcium unlock LSI balance and additional chemical doses.
Can I scan my test strip or bleach bottle?
Yes. Pool Bible uses on-device Vision OCR and Apple Intelligence when available to read test logs and bleach labels.

Ready for your next test?

Download Pool Bible free on iPhone. Core dosing stays free — no chemical upsells, no phosphate lectures.

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