Tanknote is an aquarium logbook for freshwater, planted, saltwater and reef tanks. Record water tests, maintenance and livestock without creating an account. Aquarium records work offline, with no ads.

12 INTERFACE LANGUAGES
English, Spanish, Brazilian Portuguese, German, Japanese, French, Traditional Chinese, Simplified Chinese, Italian, Indonesian, Korean and Thai. Switch languages in Settings without changing your records.

WATER TESTS AND TRENDS
• Log water parameters with reference ranges for your tank type.
• See readings on charts alongside maintenance and livestock changes.
• Mark uncertain readings when a test color is hard to interpret.

EVERYDAY AQUARIUM CARE
• Log water changes, feeding, filter care and other tasks with a tap.
• Browse past days and see maintenance that is overdue for your usual routine.
• Set local reminders for water tests and care tasks. Notification delivery depends on your device settings; the app includes a notification checkup.

LIVESTOCK, PHOTOS AND ROUTINES
• Keep fish, invertebrate, plant and coral records with quantities, dates and photos.
• Review maintenance and livestock changes on a timeline.
• Track treatments and quarantine, use acclimation timers and prepare a care sheet for someone looking after your tanks.

TOOLS AND BACKUPS
• Calculators for tank volume, water changes, salt mix and KH/calcium/magnesium dosing.
• Export CSV/JSON, or back up and restore your records and photos with a local backup file.
• Backup reminders, light and dark themes, and metric or imperial units.

FREE AND OPTIONAL PURCHASES
All features are available for up to 2 regular tanks; quarantine tanks do not count toward that limit. Tanknote Pro unlocks unlimited tanks with a one-time purchase. No subscription.
Optional contributions support development. They are separate, repeatable one-time purchases and do not unlock Pro or extra features.

YOUR RECORDS, ON YOUR DEVICE
Tanknote does not upload aquarium records or photos to developer servers. You decide when to export or share files. Google Play handles purchases and reviews; feedback email is sent only when you choose to send it.