Privacy Policy — AquariumAI

Last updated: September 13, 2026

Data controller

Sebastian Greuzinger
Email: greuzinger+aquariumai@gmail.com

Summary

AquariumAI collects no telemetry, requires no user account, and no registration. All your data (tanks, tasks, stock, photos, water parameters, dosing history) stays exclusively on your device. There is no server of ours in between.

If you use the optional AI advisor, however, a dossier of your tank does leave the device and is sent to Anthropic's Claude API — section 2 below describes exactly what it contains.

What data goes where

There are three situations in which the app talks to an external service at all — all of them strictly directly from your device, with no server of ours in between. All three are optional and off by default:

1. AI care profiles and fertilizer research (optional feature, off by default)

If you enable this feature and fetch a care profile for a species, only the species name is sent to Anthropic's Claude API (api.anthropic.com). If you have the ingredients of a fertilizer researched, the brand and name of that fertilizer go to the same interface. In both cases no tank, photo, location, or other user data is transmitted. The request uses your own, self-provided Anthropic API key (bring-your-own-key) — the app itself does not ship a key and does not earn anything from usage. Your API key is stored encrypted in the Android Keystore and leaves the device only to authenticate against the Claude API. How Anthropic processes these requests is governed by their own privacy policy (anthropic.com/legal/privacy).

2. AI advisor (optional feature, off by default)

When you start a consultation, a text dossier of your tank is sent to Anthropic's Claude API: the tank's basic data, its livestock including key figures from profiles you already fetched, recorded water parameters, dosings, the care plan and a condensed history of the last 90 days — together with the questions you ask in the dialogue. Free-text notes on tanks, livestock, tests and history are included by default and can be switched off in the settings.

Before your first consultation, a dialogue in the app explains this; you can withdraw that consent in the settings at any time. A preview shows you the complete text word for word before it is sent. Photos and your API key are never transmitted. These requests, too, use your own Anthropic key and go directly from your device.

3. Photo suggestions for stock entries (part of the same optional AI feature)

When searching for photos for a profile, the (usually scientific) species name is sent to the open Wikimedia Commons API (commons.wikimedia.org, meta.wikimedia.org) to suggest matching, license-free photos. No personal or usage data is transmitted — just the search term, like any regular web search.

What else stays local

Tank, task, stock, water-parameter and dosing data in a local database on your device.
The history of your consultations — questions, answers and the dossier that was sent — stays in that same local database and can be deleted individually in the app.
Photos you take or pick, stored in the app's internal storage.
An optional JSON backup export is stored wherever you save it — sharing it (e.g. via email attachment) is your own responsibility.

Permissions and why they're needed

Internet — only for the optional cases above (AI profile, fertilizer research, AI advisor, photo search).
Camera — for photos you take of your stock; photos are stored locally only.
Notifications, exact alarms, boot receiver, vibration, wake lock — solely for local reminders about due care tasks; no data is transmitted for this.

Sharing with third parties

Other than the cases described above, which you actively trigger yourself (Anthropic, Wikimedia), there is no sharing of data with third parties. No sale of data, no tracking, no ads, no analytics or crash-reporting services.

Your rights

Since all app data lives exclusively on your device, you're always in full control: view, change, and delete directly in the app or by uninstalling it. For questions about the two external services, contact the respective provider (Anthropic, Wikimedia) or us at the contact address above.

Changes to this policy

This page is updated when relevant app changes occur; the date above shows the last update.