Little Ocean is a logbook for your aquarium — saltwater, freshwater, or brackish.

LOG YOUR WATER TESTS
Enter whatever you tested and see instantly whether anything is outside its ideal range for your tank. Gauges show every parameter against your own target range, and trend charts show where it has been heading.

SCAN A TEST WITH YOUR CAMERA
Struggle to match the tube to the color card? Photograph the tube on the card and Little Ocean reads it for you, tells you how confident it is, and always lets you confirm or correct the value before it saves. Camera scanning is in beta — you stay in charge of every number.

UNDERSTAND WHAT YOUR NUMBERS MEAN
Ammonia, nitrite, pH, alkalinity, calcium — the app explains what is wrong, why it matters for your fish, and what to do about it, in plain language. Ask Squiggles, the built-in assistant, about anything specific to your tank.

KEEP THE WHOLE STORY IN ONE PLACE
New livestock, equipment, water changes, dosing, photos, and growth updates all land on one timeline, so you can scroll back and see exactly what happened and when.

DOSING AND MAINTENANCE THAT REMIND YOU
Set dosing schedules with container tracking and get a nudge when a bottle runs low. Schedule water changes and filter cleanings and get notified when they are due.

YOUR DATA IS YOURS
Export any tank's water tests, water changes, and dosing history as a CSV at any time.

SHARE, IF YOU WANT TO
Make a tank public, follow other keepers, and share your tank with your local fish store so they can see your parameters before you walk in. Everything is private unless you choose otherwise.

Free for anyone in the aquarist community, with no ads. Built by a keeper who kept a notebook by the tank for years and wanted something better.