A test kit gives you a number. Once.
Aquably keeps every reading you take and judges it against ranges chosen for your tank type — so ammonia, nitrite and nitrate stop being isolated numbers and start being a trend you can act on.
40 ppm nitrate is fine in a community tank
and a problem in a reef.
Aquably knows the difference. Pick your tank type and every reading is judged against the range that actually applies to it — then charted against that range, with anything out of bounds marked by shape and colour, not colour alone.
Blank means "not tested" — never zero
The most dangerous thing a logbook can do is show a confident green zero for a parameter nobody measured. Leave a field empty in Aquably and it stays empty: excluded from the health score, greyed in the chart, and blank in your CSV export.
Ranges ship for community, planted, cichlid, reef and fish-only marine tanks — and you can override any of them per tank.
A real logbook, not a note field.
Eleven parameters, recurring maintenance, livestock, charts, streaks and a backup you own — all computed on the device in your hand.
Eleven water parameters
pH, ammonia, nitrite, nitrate, temperature, salinity, KH, GH, phosphate, calcium and magnesium — only the ones that apply to your tank type are shown.
Trends with a safe band
Every parameter charts over 7, 30, 90 or 365 days against its healthy range, with out-of-range readings marked by both shape and colour.
Today & upcoming
Water changes, filter rinses and "test water" prompts appear when due — as a list you check, not a notification that nags.
Tank health score
One number per tank, weighted toward ammonia and nitrite, that fades as your readings get stale.
Weekly streaks
Streaks count weeks, not days — because testing daily is neither realistic nor good practice.
Ten achievements
Fully Cycled, Crisis Averted, Reef Ready, Clean Sweep and more — each with visible progress while it is still locked.
Search, tags & filters
Full-text search across tanks, readings, livestock and observations, with tag chips, sorting and pinned tanks.
Export you own
Full JSON backup for a lossless restore, plus wide-format CSV of readings, maintenance and tanks for any spreadsheet.
Maintenance history
Completions per week, days since the last water change, and the consistency chart that shows whether the routine is real.
Livestock & notes
Track fish, inverts, corals and plants per tank, and keep private observations in an encrypted journal.
Make it yours
Light or dark, five accents, three densities, and Celsius or Fahrenheit — all remembered between launches.
No account. No sync. No analytics. No ads.
There is no sign-up screen because there is no server. The only network request Aquably ever makes is loading this site's privacy policy when you tap it in Settings — which is the sole reason it declares the INTERNET permission at all.
Your logs are yours.
Aquably's Play Data Safety declaration is the shortest one there is: no data collected.
Bytes of your data sent anywhere
Accounts, logins or email addresses
Third-party SDKs, trackers or ads
Permission — INTERNET, for the policy page