# HYDROS App vs ReefLynk

The clearest difference is rating: ReefLynk at 5.0 against HYDROS App's 3.5. ReefLynk also leads on review sentiment (100% vs 62%) and update cadence (daily vs every 3 months). HYDROS App's advantage is in-app purchases (none vs 2) and ratings volume (24 vs 2). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. ReefLynk sells 2 in-app purchases, starting at $2.99 per month. HYDROS App asks for nothing beyond the download.

ReefLynk holds the better App Store score, 5.0 against 3.5. That said, the two scores are not equally well evidenced: HYDROS App has 24 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 62% of HYDROS App's written reviews are positive against 100% of ReefLynk's.

HYDROS App ships an update every 3 months, ReefLynk daily. The most recent releases landed on October 29, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | HYDROS App | ReefLynk |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.5 (24 ratings)](https://appshunter.io/ios/app/hydros-app/id1455344294/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/reeflynk/id6759136977/reviews)** |
| Number of ratings | **24** | 2 |
| Positive reviews | 62.3% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Daily** |
| Monetization | **Free** | Freemium |
| Size | 70 MB | 22 MB |
| Requires iOS | 15.6 | **15.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Coralvue](https://appshunter.io/developer/1455344293) | [MICHAEL KARL TAYLOR](https://appshunter.io/developer/1877026250) |

## What reviewers say

### HYDROS App

[App page](https://appshunter.io/ios/app/hydros-app/id1455344294)

Easily monitor and control your aquarium's vital parameters like temperature, pH, and salinity. Manage all your connected devices, including ATOs, lights, and pumps, with a user-friendly interface. Quick setup with preset configurations means no coding is required to get your system running.

**Highlights:** Monitor temperature, ORP, pH, salinity, Control ATO, lights, heaters, pumps, User-friendly interface, Quick setup with presets, Manage multiple devices and aquariums, Set schedules and create modes

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

**In-app purchases:** none


### ReefLynk

[App page](https://appshunter.io/ios/app/reeflynk/id6759136977)

Manage your reef aquarium with this comprehensive app. Track water parameters, schedule maintenance, and catalog your livestock with photos. Syncs across devices and offers email reminders to keep your tank healthy.

**Highlights:** Water parameter tracking, Maintenance scheduling, Livestock cataloging, Real-time device sync, Email reminders

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| ReefLynk Pro | $2.99 | per month |
| ReefLynk Pro Yearly | $29.99 | per year |


## Frequently asked questions

### Is HYDROS App free?

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

### Is ReefLynk free?

ReefLynk is free to download, with in-app purchases available.

### Which has better reviews, HYDROS App or ReefLynk?

ReefLynk is rated higher. HYDROS App averages 3.5 out of 5 from 24 ratings, while ReefLynk averages 5.0 from 2 ratings.

### Do HYDROS App or ReefLynk have ads?

Neither HYDROS App nor ReefLynk shows ads.

### Which is updated more often, HYDROS App or ReefLynk?

HYDROS App ships an update every 3 months, and ReefLynk daily. Most recently, HYDROS App was updated on October 29, 2026 and ReefLynk 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.*