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Spa Calc vs. The Rest
Most hot tub apps are either a remote for one brand's heater or a strip reader for one brand's chemicals. Spa Calc is for the water itself: is it safe to soak, what to add in teaspoons, and when to drain, for any tub and any brand.
Each comparison below was checked against the other app's own App Store page on 28 October 2026. Every page also says when the other app is the better choice. For a ranked overview, see the best hot tub apps (2026).
One page per app
- Spa Calc vs Bestway (Lay-Z-Spa) Inflatable tub remote Bestway Connect (SmartSpa): 4.6 stars from 1K ratings; Bestway Smart Hub: 1.7 stars from 260 ratings (US App Store) Remote control for a Wi-Fi Lay-Z-Spa's heater, filter and bubbles. Spa Calc tells you if the water is ready and what to add.
- Spa Calc vs INTEX Link Inflatable tub remote 2.2 stars from 17 ratings on the US App Store Remote heater and schedule control for Wi-Fi PureSpa models. Spa Calc tells you if the water is ready and what to add.
- Spa Calc vs Pool Math Pool app with spa mode 3.6 stars from 287 ratings on the US App Store A pool calculator that can hold spa configurations on Premium. Spa Calc is made for hot tubs, with one tub free.
- Spa Calc vs FROG Water Care Brand app, 4.9K ratings 4.5 stars from 4.9K ratings on the US App Store Strip readings and dosing guidance for FROG systems, with sign-in. Spa Calc works with any sanitizer and kit, no account.
- Spa Calc vs HTH Brand app with spa testing 4.7 stars from 4.1K ratings on the US App Store (pool and spa app) Free strip testing for HTH pool and spa strips with product picks. Spa Calc is hot tubs only, with any kit and no account.
- Spa Calc vs Clorox Pool Pool app 4.6 stars from 29K ratings on the US App Store (pool app) A popular pool app whose listing doesn't describe hot tubs. Spa Calc is built for tubs, inflatables included.
- Spa Calc vs Orenda Pool LSI calculator 4.7 stars from 477 ratings on the US App Store A free, well-rated pool LSI calculator; we found no hot tub mode described. Spa Calc is made for tubs.
One hot tub free, every feature. No account. No ads.
One tub, inflatables included, gets the soak check, doses in teaspoons, bromine or chlorine, the drain countdown, the full log and charts, reminders, PDF and CSV export and iCloud backup for free. Plus covers up to 10 tubs for rental hosts at $1.99 a month, $14.99 a year or $39.99 once. Pro covers unlimited tubs for service techs at $9.99 a month or $79.99 a year. On the App Store at launch.
Bestway, Lay-Z-Spa, Intex, INTEX Link, PureSpa, Pool Math, TroubleFreePool, FROG, HTH, Clorox and Orenda are trademarks of their respective owners. Spa Calc is not affiliated with them. Information checked on 28 October 2026; prices and features change. Corrections: [email protected]