Reef Tank Log

Reef Tank Log is a private, focused aquarium journal for recording water tests, livestock, equipment, care, and observations in one place.

Record alkalinity, calcium, magnesium, nitrate, phosphate, pH, salinity, and temperature in a fast water-test flow. See the latest readings on your tank dashboard, review changes over time, and compare your entries with the personal target ranges you set. Values are records you enter, not automatic measurements, dosing advice, or safety conclusions.

Keep your reef history organized:

- log unlimited core water tests for one tank in the free app;

- review reading history and 7-day or 30-day trends;

- edit saved readings and remove test sessions with Undo;

- save livestock and equipment details, notes, dates, status, and photos;

- search, filter, sort, archive, and restore collection records;

- create one-time or repeating care tasks;

- mark care complete and keep a completion history;

- log water changes, dosing, feeding, and reef observations;

- enable local, inexact reminders when you choose;

- export tests, livestock, equipment, care, and activities as CSV;

- switch between light, dark, and system themes;

- display temperature in Celsius or Fahrenheit and tank volume in litres or gallons;

- delete all local reef records from Settings.

Reef Tank Log Pro is an optional one-time purchase. Pro unlocks multiple tanks, custom parameters, longer trend ranges and parameter comparison, unlimited livestock and equipment records, photo timelines, unlimited reminders, dosing templates, and creation of complete local backups including app-owned photos. Validated restore and complete CSV export remain free. The localized price is supplied by Google Play. There is no subscription and there are no ads.

Your reef records stay on your device unless you explicitly export or back them up. The app has no account, cloud sync, analytics SDK, advertising SDK, or developer-operated crash reporting. Photos are selected through Android's Photo Picker and copied into app-private storage. CSV and backup files are created only through Android's document picker when you request them.

Reef Tank Log is an organizational tool. You are responsible for data accuracy and aquarium care decisions. It does not replace product instructions or advice from a qualified aquarium professional.