Pool Calculator support

Answers to common questions about Pool Calculator for iPhone and Android.

Frequently asked questions

Where do the target levels come from?

From the TroubleFreePool (TFP) method, the approach used by the TFP community and its Pool Math calculator. Free chlorine targets depend on your CYA (stabilizer) level, pH is aimed at 7.5, and alkalinity, calcium, CYA and salt targets follow the TFP "ideal pool levels" guidance for your surface type and sanitizer. You can read more at troublefreepool.com.

Why are the doses different from my pool store or another calculator?

Three things usually explain it: the target (TFP ties chlorine to CYA, which many store calculators ignore), the product strength (10% liquid chlorine versus 12.5%, for example, or 31.45% muriatic acid versus a weaker blend), and your pool volume. Check the pool's volume and the product strength you selected first. Store calculators are also often written to sell a specific product.

Is it safe to follow the app's doses exactly?

Treat them as estimates. Always read and follow the product label, which is the legal instruction for that product. Add chemicals to water (never the other way round), never mix chemicals, add acid slowly in front of a return jet with the pump running, and retest before the next step. pH chemistry in particular is approximate, which is why the app suggests adding about three quarters of a pH dose, waiting 30 minutes with the pump on, and retesting.

Why does the app tell me to do one thing first?

Some chemicals affect more than one reading. Acid lowers alkalinity as well as pH, cal-hypo adds calcium, and dichlor or trichlor add CYA. The dosing plan is ordered so that each step accounts for the previous one, and it asks you to retest between steps because one change affects the next.

How do I find my pool's volume?

Open your pool profile and use the volume helper. Enter the length, width (or diameter) and average depth for rectangle, round, oval or kidney shapes. Average depth is roughly (shallow end + deep end) divided by two. If the builder told you the volume, you can type it in directly.

What does salt-water generator (SWG) mode change?

With a salt cell, TFP uses a higher CYA target (60 to 90 ppm) and a lower free-chlorine range, and adds a salt target. SWG mode applies those targets and shows a salt dose. It is part of Pro.

What is free and what is Pro?

Free includes one pool, full dosing for your latest test, and 30 days of history and charts. Pro unlocks multiple pools, SWG mode, history beyond 30 days, dosing for older tests and test reminders. Pro is a weekly subscription with a free trial, or an annual subscription, billed by the App Store or Google Play.

How do I restore a purchase on a new phone?

Sign in to the same Apple ID or Google account you bought it with, then go to Settings, open the Pro screen and tap "Restore purchases". Subscriptions are managed in your App Store or Google Play account settings. If you want to move your readings too, export a JSON file from Settings before you switch; your data lives only on your device (see the privacy policy).