# FREE Drum Filter vs KoiAi

The clearest difference is in-app purchases: FREE Drum Filter at none against KoiAi's 1. FREE Drum Filter also leads on ratings volume (3 vs 1) and iOS requirement (14.0 vs 18.4). KoiAi's advantage is update cadence (every 2 weeks vs every 21 months). On price, rating, ads and device support there is nothing between them.

Both are free to download. KoiAi sells 1 in-app purchase, starting at $2.99 per month. FREE Drum Filter asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 5.0 for FREE Drum Filter against 5.0 for KoiAi. Both are backed by a comparable volume of ratings — 3 and 1 respectively.

FREE Drum Filter ships an update every 21 months, KoiAi every 2 weeks. The most recent releases landed on October 2, 2026 and October 28, 2026 respectively.

## The numbers

| Metric | FREE Drum Filter | KoiAi |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (3 ratings)](https://appshunter.io/ios/app/free-drum-filter/id1597472915/reviews) | [5.0 (1 ratings)](https://appshunter.io/ios/app/koiai/id6749480399/reviews) |
| Number of ratings | **3** | 1 |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 21 months | **Every 2 weeks** |
| Monetization | **Free** | Freemium |
| Size | 17 MB | 4 MB |
| Requires iOS | **14.0** | 18.4 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Tu Tran Anh](https://appshunter.io/developer/1597473247) | [Geeksdobyte](https://appshunter.io/developer/1795589439) |

## What reviewers say

### FREE Drum Filter

[App page](https://appshunter.io/ios/app/free-drum-filter/id1597472915)

This application works with an IoT box to monitor and control a specialized mechanical filter for Koi ponds. It automatically removes debris and fish waste, providing real-time status updates and alerts for connection, operation, and water levels.

**Highlights:** Real-time monitoring of connection and operation status, Push notifications for alarms and warnings, Control of automated washing cycles, Water level status monitoring, Rinse cycle counting and logging, Support for multiple devices, Dual language support (English/Vietnamese)

**In-app purchases:** none


### KoiAi

[App page](https://appshunter.io/ios/app/koiai/id6749480399)

Manage your koi pond with this comprehensive app. Track water quality, koi health, and expenses. Utilize AI-powered troubleshooting and photo analysis for expert guidance and early disease detection.

**Highlights:** Daily pond logging, Koi profile management, Expense tracking, Smart analytics, AI-powered troubleshooting, Photo illness detection, Expert guidance

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Monthly | $2.99 | per month |


## Frequently asked questions

### Is FREE Drum Filter free?

FREE Drum Filter is free to download, with no in-app purchases.

### Is KoiAi free?

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

### Which has better reviews, FREE Drum Filter or KoiAi?

FREE Drum Filter and KoiAi are both rated 5.0 out of 5 on the App Store, from 3 and 1 ratings respectively.

### Do FREE Drum Filter or KoiAi have ads?

Neither FREE Drum Filter nor KoiAi shows ads.

### Which is updated more often, FREE Drum Filter or KoiAi?

FREE Drum Filter ships an update every 21 months, and KoiAi every 2 weeks. Most recently, FREE Drum Filter was updated on October 2, 2026 and KoiAi on October 28, 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.*