Comparison

Spa Calc vs Clorox Pool for Hot Tubs

People search for the Clorox Pool app for hot tubs because it's one of the most popular pool apps, with 29K ratings. Its App Store description is about pool care, though, and doesn't list hot tub support. Spa Calc is built only for hot tubs. Here's the difference for a tub owner.

Prices, features and ratings checked on 28 October 2026.
App Store rating as shown on 28 October 2026: 4.6 stars from 29K ratings on the US App Store (pool app).

The short answer

Clorox Pool is a well-liked pool app, and its listing doesn't claim to handle hot tubs. If you have a hot tub, use an app made for one. Spa Calc is free for one tub, inflatables included.

At a glance

From each app's own App Store page and website, checked on 28 October 2026. "Not listed" means we found no mention of it there, not that the feature is missing.
Feature	Spa Calc	Clorox Pool
Price	Free for one tub	Free
Hot tub support	Yes Hot tubs, swim spas, plunge tubs, inflatables	Not listed ; earlier notes said not meant for spas
Read a strip from a photo	No	Yes (pool strips)
"Ready to soak?" check	Yes	Not listed
Bromine	Yes	Not listed
Dichlor then bleach tracker	Yes	Not listed
MPS shock with wait timer	Yes	Not listed
Post-soak top-up	Yes "I just soaked"	Not listed
Doses in teaspoons	Yes	Not listed
Any brand at any strength	Yes	Not listed
Drain and refill countdown	Yes	Not listed
Inflatable presets	Yes	Not listed
Test history	Yes Every test, with charts	Yes Last 10 water analyses
Reminders	Yes Test, filter and drain	Yes Maintenance reminders
Product shopping links	No	Yes Walmart, Amazon, Lowe's.com
Account to sign up for	None	Not listed in current description

Pricing

Our app

Spa Calc

Free$0Every feature for one tub, inflatables included.
Plus$1.99 a month, $14.99 a year or $39.99 onceUp to 10 tubs plus the host and pro tools. 1-week free trial on the yearly plan.
Pro$9.99 a month or $79.99 a yearUnlimited tubs plus the host and pro tools. 1-month free trial on the yearly plan.

Prices on the App Store at launch. Pricing is per person, not per tub.

Pool strip-scanning app

Clorox Pool

Clorox Pool appFreePool strip scanning or manual entry, product and dosage recommendations, Pool Plan, reminders, last 10 water analyses.

Free on the App Store. No in-app purchases listed.

Prices as listed on 28 October 2026. Source

Both are free for one body of water. Spa Calc is paid only for more than one tub.

A hot tub isn't a small pool

A tub holds a few hundred gallons at around 100 °F, with several people in it at once. Sanitizer burns off faster, doses are tiny, and the water needs draining on a schedule. Spa Calc is built around that: a soak check before you get in, a top-up after you get out, and a drain date from your tub's size and use.

Bromine or chlorine

Spa Calc handles bromine with a bromide bank, chlorine with dichlor then bleach (or bleach only), MPS shock, and salt, ozone, UV and mineral systems.

Every test kept

Spa Calc keeps every test, dose, soak, drain and filter rinse, with charts up to a year, free for one tub.

What Clorox Pool Users Complain About

Paraphrased from public reviews. Each one links to where it was posted and gives the month it was written.

No spa option. A 2018 reviewer bought spa test strips with packaging that showed the app, then found "the app does not work for spas" (App Store review, August 2018). That review is old, but the current description still doesn't list hot tubs.

Spa Calc approach: hot tubs only, from the first screen.

When Clorox Pool is the better choice

You need a pool app, not a hot tub app, and want strip scanning with product picks.
For a pool, see our pool app, Pool Calc, and its comparison with Clorox Pool.

Questions people ask

Does the Clorox Pool app work for hot tubs?

Its current App Store description is about pool care and doesn't list hot tub support, and earlier release notes said the app wasn't meant for spas (checked 28 October 2026). A 2018 reviewer bought spa strips that showed the app on the packaging and found no spa option.

What app should I use for my hot tub chemicals?

Use an app made for tubs, because a hot tub's small volume, heat and heavy use change the doses. Spa Calc gives one tub every feature free: a soak check, doses in teaspoons, bromine or chlorine, and a drain countdown. It is on the App Store at launch.

Can I use pool chemicals in a hot tub?

Many are the same chemicals sold in different strengths and pack sizes. A hot tub needs far smaller amounts, so dose by your tub's volume and the product's strength, and follow the label and your tub maker's instructions.

More comparisons

All comparisons

References

Clorox and Clorox Pool 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]