What’s new

• Custom target ranges Pro Set your own ranges for pH, alkalinity, calcium hardness, CYA, and free chlorine. Choose “Custom Ranges” under Climate Zone in Settings, and leave any field blank to keep the standard default. Recommendations, your Health Score, and the widget all follow your ranges. The LSI target still comes from your pool surface type.
• Faster widget refresh. The Home Screen widget now updates as soon as you save your settings.

• New methodology page showing where every number on this site and in the app comes from: published sources, the FC/CYA and LSI formulas, worked examples, and limits.

• Borate tracking Pro Opt in from Settings to log borate levels, see a 30–50 ppm target range, and get a heads-up when levels drift out of range. Requires separate borate test strips.

• More accurate LSI. Corrected the temperature and calcium factors in the Langelier Saturation Index calculation. Past readings are recalculated automatically.

• Light and dark mode. The app follows your device’s display setting automatically.
• Reference-tab dosing amounts for muriatic acid, soda ash, and calcium chloride now match what the recommendation engine calculates.

• Liquid chlorine strength Pro Set your product’s concentration (6%, 10%, or 12.5%) so doses match the jug in your hand.
• Fixed a combined-chlorine recommendation that suggested boosting chlorine when free chlorine was already at or above target.

Versions 1.18.2 – 1.20.2 · July 6–17

• Home Screen widget showing FC, pH, and your Health Score at a glance (small and medium sizes).
• Pool surface type (plaster, pebble, vinyl, or fiberglass) so LSI targets fit your pool.
• Predictive reminders when FC is running low or pH is drifting high, especially useful for saltwater pools. Reminders moved to the Tasks tab.
• Smarter dosing. When a drain is needed to lower CYA, chlorine is no longer pushed toward an inflated target. High pH and alkalinity now combine into one acid-then-aerate step instead of double-dosing acid.
• Recalibrated the muriatic acid recommendation, which had been calculating doses too high.
• A “Check LSI Balance” card after logging, and an app-icon badge when a reminder is due Pro
• Pro unlock now stays active after app updates, plus a tab-bar scrolling fix.

Versions 1.12.1 – 1.18 · June 4–29

• Tasks tab: equipment maintenance tracker for skimmer, pump basket, filter, and salt cell, with due dates and overdue alerts. Completion history and custom intervals for Pro.
• Filter pressure tracker: log baseline and current PSI to know when to backwash.
• Free chlorine thresholds scale with CYA, so pools with higher stabilizer get correct minimums and swim-safe guidance. See the FC/CYA ratio.
• Clearer recommendations: no more conflicting chlorine and shock advice; pH and alkalinity cards explain that one acid dose lowers both; CYA and calcium drains are flagged together so you can do one drain.
• Learn as you go: tap ⓘ on any log field or recommendation card for a plain-language explanation. Shock and chlorine boosts show a starting-dose calculation.
• Redesigned log form, recalibrated doses for muriatic acid, baking soda, stabilizer, and salt, and a wider 2,700–4,000 ppm salt range for saltwater pools.
• Reminders now fire reliably on schedule. Corrected the desert-climate pH range. Saltwater tips only appear for saltwater pools.
• The free tier now includes 5 complete water tests with full recommendations.
• Android 1.18 brought the Tasks tab, equipment reminders, and a filter type setting to Android.

Versions 1.6 – 1.12 · April 30 – May 24

• CYA-adjusted chlorine targets with climate-adjusted ranges, shock levels based on breakpoint chlorination, and warnings when trichlor tabs are building up CYA.
• Combined chlorine: enter CC from a DPD test, or TC from a pool store report, and the app calculates the other.
• Edit past readings and a Health Score chart over time.
• Recommendation order fixed so CYA is always addressed before chlorine. Calcium drain advice only appears when water is actually scale-forming.
• Inventory accepts any item by name, plus algaecide, clarifier, and metal remover.
• Save warnings when a missing reading (like CYA) would affect your dosing.