# Mars Hydro vs GrowDiary

The clearest difference is ads: Mars Hydro at none against GrowDiary's shown. GrowDiary's advantage is update cadence (every 9 days vs monthly). On price, in-app purchases, device support and iOS requirement there is nothing between them.

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

Mars Hydro ships an update monthly, GrowDiary every 9 days. The most recent releases landed on October 13, 2026 and October 2, 2026 respectively.

## The numbers

| Metric | Mars Hydro | GrowDiary |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[2.6 (27 ratings)](https://appshunter.io/ios/app/mars-hydro/id6479227564/reviews)** | — |
| Number of ratings | **27** | — |
| Positive reviews | 23.8% of reviews | — |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | Monthly | **Every 9 days** |
| Monetization | Free | — |
| Size | 45 MB | 46 MB |
| Requires iOS | **15.0** | 16.4 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 4+ | 17+ |
| Developer | [MARS TRADING RCC, INC.](https://appshunter.io/developer/1726858942) | [GrowD soft s.r.o.](https://appshunter.io/developer/1784239247) |

## What reviewers say

### Mars Hydro

[App page](https://appshunter.io/ios/app/mars-hydro/id6479227564)

Control your smart grow system with this app. Manage LED lights, ventilation, and monitor environmental data like CO2, temperature, and humidity for optimal plant growth. Automate your entire grow kit to mimic natural conditions.

**Highlights:** LED light control with timers and simulation, Ventilation system management, Complete grow kit automation via iHub, Environmental data monitoring (CO2, temp, humidity, PPFD), Sunrise and sunset simulation

**In-app purchases:** none


### GrowDiary

[App page](https://appshunter.io/ios/app/growdiary/id6739211123)

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

**In-app purchases:** none


## Frequently asked questions

### Is Mars Hydro free?

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

### Is GrowDiary free?

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

### Do Mars Hydro or GrowDiary have ads?

GrowDiary shows ads; Mars Hydro does not.

### Which is updated more often, Mars Hydro or GrowDiary?

Mars Hydro ships an update monthly, and GrowDiary every 9 days. Most recently, Mars Hydro was updated on October 13, 2026 and GrowDiary on October 2, 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.*