# EcoJar: Fish Tank Simulator — Aquarium sim in a sealed jar

> Aquarium sim in a sealed jar (iPhone/iPad app by Kunliang Wu.)

- Source: https://appshunter.io/ios/app/ecojar-fish-tank-simulator/id6805503292 (this page in markdown: same URL + `.md`)
- Developer: [Kunliang Wu](https://appshunter.io/developer/1700080230)
- Category: Entertainment
- Price: $1.99
- Age rating: 4+
- Requires: iOS 15.1 · 35 MB
- Languages: American English
- Released: 2026-09-04
- Data updated: 2026-09-07
- User reviews in markdown: https://appshunter.io/ios/app/ecojar-fish-tank-simulator/id6805503292/reviews.md

## What is EcoJar?

A sealed glass jar. Sand, water, algae, a few daphnia. Then you leave it alone and find out whether it holds.

EcoJar is an aquarium made of cellular automata. Every grain of sand falls, every bubble rises, every alga photosynthesizes, one cell at a time. Nothing here is decoration and nothing runs on a timer: if the oxygen falls, it fell because something in your jar breathed it.

WHAT IS ACTUALLY SIMULATED
- Oxygen and carbon dioxide as real quantities, produced and consumed cell by cell
- Photosynthesis that follows the light, so algae stop making oxygen at night
- Fish that suffocate when the water cannot keep up with them
- Twelve materials that all behave: sand, stone, wood, glass, water, algae, grass, bacteria, daphnia, zooplankton, fish, goldfish, plus Clear and Cut for taking things back out again

WHAT IS NOT SIMULATED
There is no water temperature reading, because this simulation does not model temperature. We would rather say so than print a number that means nothing.

WHAT IT ASKS OF YOU
Nothing. There is no score, no daily reward, no timer to come back for. Build a jar, watch the oxygen curve, and decide for yourself whether it is a good one.

PRIVACY
No account. No analytics. No advertising identifier. No network request of any kind. The simulation runs entirely on your device, and your jar is stored in this app's own storage. Uninstalling deletes it.

Note: EcoJar is an independent app built on the open-source orb.farm simulation engine by Max Bittker, used under the MIT license. It is not affiliated with or endorsed by the original author. The full license text is included in the app under About.


## Version history (last 1 release)

### 1.0 — 2026-09-04

No release notes.

## More apps by Kunliang Wu

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All apps by Kunliang Wu: https://appshunter.io/developer/1700080230

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-07.*