Tankbook: Aquarium Log

Log water tests in seconds, spot trends at a glance, never miss a water change. No account. No subscription. Your data stays on your phone.

Tankbook is your aquarium's journal: log water parameters in seconds, see trends at a glance, and get maintenance reminders. Built for fishkeepers who want a reliable tool — not another subscription.

FAST LOGGING • All your parameters on one screen: pH, temperature, ammonia, nitrite, nitrate, GH and KH • Last value shown as reference, numeric keypad, save in one tap • UNLIMITED measurements, free forever

CLEAR TRENDS • One chart per parameter with its healthy range shaded • Catch an ammonia spike or creeping nitrates before they hurt your fish

MAINTENANCE ON AUTOPILOT • Reminders for water changes, filter cleaning, dosing or pruning • Complete a task and it's logged to history; the next reminder reschedules itself

YOUR DATA IS YOURS • No account, no sign-up, no cloud: everything lives on your phone • Full CSV export, free forever • We collect no data — literally none

FREE AND PAID, NO FINE PRINT • Free: 1 tank, unlimited measurements, CSV export, 2 reminders, 30 days of trends • Tankbook Lifetime ($9.99, ONE-TIME purchase): unlimited tanks, unlimited reminders and full trend history. No subscription, ever.

Freshwater first: made for community tanks, planted tanks, bettas and shrimp keepers. Missing a parameter? Tell us — the app grows with the community.