Tired of Guessing With Test Strips?
There’s an easier way to care for your water.
- Manual testing is inconsistent and hard to trust.
- You never really know how much to add — or when.
- Poor water balance can damage your spa or irritate your skin.
How Sutro Solves It
A Smarter Way to Care for Your Spa
The Sutro Smart Monitor is a floating device that automates your spa water testing. Instead of dipping test strips and second-guessing, Sutro gives you precise, professional-grade results — and tells you exactly what to add, right from your phone. It's the easiest way to enjoy consistently balanced water, with none of the guesswork.
Who It's For
Just drop it in. Your spa’s ready when you are.
No strips. No second guessing. Sutro tests automatically, then tells you exactly what to add — so you can soak, not stress.
"This device and the service are the best way to keep my spa in tip-top shape... Perfect recommendations every time...."
How It Works
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Monitor
The Smart Monitor is a device that floats in your spa and performs the tests. It contains a rechargeable battery.
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Cartridge
Powered by reagents from LaMotte (the gold standard for water testing for 100+ years)
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Hub
The hub sits inside your house; it receives the tests via WiFi and sends them to Sutro's servers, which calculates recommendations and sends to the App.
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App
View your water test results, recommendations, and historical data (premium plan only) from your Smartphone anywhere, anytime.
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Subscription
Your subscription covers replacement cartridges as needed, and app access and features.
What Spa Owners are Saying
Simple Setup. Ongoing Support.
Follow our guide on how to set up your Sutro, including troubleshooting any issues along the way.
Ready to Simplify Your Water Care?
- Automatically test your spa water 3x a day with lab-grade accuracy
- Get exact chemical instructions sent straight to your phone
- Enjoy clean, balanced water — without test strips or confusion
QUESTIONS & ANSWERS
Frequently Asked Questions
Sutro takes 3 readings daily at 11am, 7pm, and 3am EST.
After initial setup, Sutro also takes a reading immediately.
The Sutro takes readings for chlorine or bromine, pH, and total alkalinity.
The best distance between the monitor and hub is 30-40ft from your spa, but closer is better.
The distance can sometimes be up to 50ft, but this depends on walls/interference between and runs the risk of missing readings or device disconnections.
Currently, you cannot request individual readings. However, if you have the Premium Subscription, you can customize your daily test times.
In the app, open settings and select "Timing" to adjust test times.
If you have the Premium Subscription, you can change your Sutro test times.
In the app, open settings and select "Timing" to make changes.
The Sutro Cartridge measures chlorine or bromine, pH, and total alkalinity using 5 reagents: 2 are used for chlorine/bromine, 2 for alkalinity, and 1 for pH.
The cartridge has 3 reaction chambers that use magnetic mixing balls to mix the reagents with the water.
The reagents are similar to the ones in liquid drop test kits. The chlorine/bromine is measured using the DPD method, the pH with phenol red, and alkalinity using titration with a mixed pH indicator.
Currently, you cannot buy individual Sutro Cartridges.
Sutro works with all chemicals in their database, which includes our Jacuzzi chemical line.
A complete list of chemicals can be found on Sutro's website.
There are 2 subscription plans available:
Basic
- Replacement cartridges shipped when you need them.
- Access to the Sutro app and their support team
Premium
- Everything in Basic.
- Priority support with a certified CPO (Certified Pool/Spa Operator).
- Weekly water health report
- Monthly Pool consultation (on request).
- Advanced analytics.
There isn't a seasonal subscription, but can pause and resume your subscription at any time.
- Log in to your account at hottubstore.ca.
- Click the account icon at the top right of the page.
Desktop: Click Manage Subscriptions.
Mobile: Click Account and scroll down to find Manage Subscriptions. - Click on your subscription.
- At the bottom right of your subscription, click the Pause my subscription button.
Currently, the Sutro app only supports English and French.
Sutro is currently compatible with Google Assistant, for Google Home.
Note: your Sutro email needs to be the same as your Google account.
To Set up:
- Open Google Assistant.
- Type or Say "Talk to Sutro Smart Home."
- Login using Google, and it's connected.
To use, say "Okay Google, talk to my Sutro Smart Home."
Then you can ask:
- What are my latest readings?
- What's my pool temperature?
- What are my latest recommendations?
Sutro is not yet available on Alexa or Apple Home.