# Sutro vs Purezone by Balboa

The clearest difference is rating: Purezone by Balboa at 5.0 against Sutro's 3.9. Purezone by Balboa also leads on update cadence (weekly vs every 2 months). Sutro's advantage is ratings volume (175 vs 3). On price, ads, in-app purchases and monetization model there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Purezone by Balboa holds the better App Store score, 5.0 against 3.9. That said, the two scores are not equally well evidenced: Sutro has 175 ratings behind it against 3, so its average is the more settled of the two.

Sutro ships an update every 2 months, Purezone by Balboa weekly. The most recent releases landed on October 15, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Sutro | Purezone by Balboa |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.9 (175 ratings)](https://appshunter.io/ios/app/sutro/id1439627399/reviews) | **[5.0 (3 ratings)](https://appshunter.io/ios/app/purezone-by-balboa/id6737352989/reviews)** |
| Number of ratings | **175** | 3 |
| Positive reviews | 72.9% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Weekly** |
| Monetization | Free | Free |
| Size | 39 MB | 104 MB |
| Requires iOS | **12.4** | 13.0 |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Sutro Connect Inc](https://appshunter.io/developer/1439627398) | [WaterGuru, Inc](https://appshunter.io/developer/1153080819) |

## What reviewers say

### Sutro

[App page](https://appshunter.io/ios/app/sutro/id1439627399)

Effortlessly manage your pool or spa water quality. This app works with a smart monitor to automatically track pH, free chlorine, alkalinity, and temperature, providing insights that make sense for optimal water conditions.

**Highlights:** Automatic water quality monitoring, pH tracking, Free chlorine measurement, Alkalinity tracking, Temperature monitoring, Seamless app integration

**In-app purchases:** none

**What reviewers like**

- 🚀 Easy to use
- 👍 Accurate water testing
- 💡 Helpful notifications and recommendations
- 🔒 Reliable customer support
- 🚀 Convenient pool monitoring

**What reviewers complain about**

- 🐛 Connectivity issues
- 🐛 Inaccurate readings
- 🐛 Buggy app performance
- 🔋 Expensive subscription
- 🐛 Setup difficulties

**Reported bugs**

- App crashes and freezes
- Disconnection issues with hub
- Calibration failures
- Inaccurate water chemistry readings

**Requested features**

- Measure total hardness and CYA
- Customizable notification settings
- Ability to cancel subscription easily
- Improved app stability and user experience


### Purezone by Balboa

[App page](https://appshunter.io/ios/app/purezone-by-balboa/id6737352989)

Automate hot tub water maintenance with real-time insights and recommendations. This system simplifies keeping your water balanced and safe for optimal enjoyment.

**Highlights:** Smart monitoring system, Automated maintenance, Real-time insights, Water chemistry recommendations, Simplified water balancing

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Sutro free?

Sutro is free to download, with no in-app purchases.

### Is Purezone by Balboa free?

Purezone by Balboa is free to download, with no in-app purchases.

### Which has better reviews, Sutro or Purezone by Balboa?

Purezone by Balboa is rated higher. Sutro averages 3.9 out of 5 from 175 ratings, while Purezone by Balboa averages 5.0 from 3 ratings.

### Do Sutro or Purezone by Balboa have ads?

Neither Sutro nor Purezone by Balboa shows ads.

### Which is updated more often, Sutro or Purezone by Balboa?

Sutro ships an update every 2 months, and Purezone by Balboa weekly. Most recently, Sutro was updated on October 15, 2026 and Purezone by Balboa on October 24, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*