Soak: Hot Tub & Spa Calc

Balance Chlorine, Bromine & pH

Free · In‑App Purchases · Designed for iPad. Not verified for macOS.

Brand-aware hot tub chemistry. Bromine or chlorine, after-use top-ups, weekly shock — all the math, none of the upsell. Pay once. No subscription. Pay once. No subscription, no ads, no account. Works offline. Soak is the iOS hot tub chemistry assistant. Enter your test readings — free chlorine or bromine, pH, alkalinity, calcium — and get exact doses scaled to your tub volume. Brand-aware: pick the chlorine product on your shelf and Soak does the math. Features • Brand-aware dose math for Cal-hypo 68%, Dichlor 56%, Liquid chlorine 12.5% • Bromine and chlorine sanitizer support, with sanitizer-specific target ranges • Test & Adjust: enter readings, get exact doses + plain-English advisories • After-Use Dose: scale top-up by people × hours in the tub • Weekly Shock guide with chlorine and non-chlorine (MPS) paths • Locale-aware metric/imperial units (grams/ml or oz/fl oz) • pH lowerer pick: dry acid or muriatic acid (31.45%) • Out-of-range advisories so a broken test kit doesn't dose you wrong • Universal app for iPhone and iPad For hot tub owners who don't want to download a sales pitch. Bromine or chlorine, 250–500 gallon home spas, 950–1900 liter European tubs. $3.99 one-time. No subscription, no ads, no account, no cloud. Privacy: Soak collects nothing. No analytics, no accounts, no network requests. Your settings live on your device.

Ratings & Reviews

  • 5.0
    out of 5
    2 Ratings

You can now unlock Soak Pro at any time from Settings, without waiting for the trial to end. Plus small reliability improvements.

Version 1.3

The developer, Roman Kopaliani, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Not Collected

    The developer does not collect any data from this app.

    Privacy practices may vary, for example, based on the features you use or your age. Learn More

    Accessibility

    The developer has not yet indicated which accessibility features this app supports. Learn More

    Information

    Seller
    • Roman Kopaliani
    Size
    • 1.3 MB
    Category
    • Utilities
    Compatibility
    Requires iOS 17.0 or later.
    • iPhone
      Requires iOS 17.0 or later.
    • iPad
      Requires iPadOS 17.0 or later.
    • Mac
      Requires macOS 14.0 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 1.0 or later.
    Languages
    English and 5 more
    • English, French, German, Italian, Japanese, Spanish
    Age Rating
    4+
    In-App Purchases
    Yes
    Copyright
    • © 2026 Roman Kopaliani
  • Privacy Policy

    • More by Roman Kopaliani

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