How it works

From test tube to trend in three steps

There is no onboarding wizard and nothing to connect. The app is useful on the first launch, and more useful every week you keep using it.

iOS 17.0+OfflineNo account
Step 01

Create a tank, once

Name, volume, and the parameter ranges you consider normal for that tank. Ninety seconds, and it is the only setup the app asks for. Every log afterwards is attached to this tank, which is why three years of history stays readable.

  • Parameter ranges per tank — 7.2 pH is normal in one tank and a problem in another.
  • Volume in gallons or litres — used for water-change percentages.
  • Optional setup date — useful when you are still inside the first cycle.
Step 02

Log the test while the tube is still wet

Five fields, filled from your last entry. If you tested fewer parameters this week, log fewer parameters — a partial entry is still an entry, and the app will not nag you to fill in blanks.

  • Pre-filled checklist — change the numbers that moved, save.
  • Notes field — “shrimp molting”, “new filter”, “dosed Prime”.
  • Custom parameters — GH, KH, salinity, phosphate, CO₂.
// one entry, five readings, 20 seconds { "tank": "20G Community", "date": "2026-10-28", "ph": 7.2, "ammonia": 0, "nitrite": 0, "nitrate": 20, "temp_c": 25.4 }
Step 03

Let the schedule carry the routine

Reminders are per tank: a 5-gallon changes 30–50% weekly, a planted 20 might go fortnightly. Overdue work does not disappear — it sits on the Today screen until you confirm it.

Due vs overdue

Upcoming work is a nudge. Overdue work is a state — the tank card changes and stays changed until the task is done or rescheduled.

Out-of-range readings

Readings outside the range you set surface next to the tank, with the previous value for context. The app does not diagnose — it points at what changed.

Trends over 7, 30, 90 days

One line per parameter per tank. Rising nitrate over three weeks is a different problem from nitrate being 20 once.

FAQ

Practical questions

How long does one entry take?
About twenty seconds once the tank exists: open the app, tap the tank, tap the parameters you tested, type the numbers, save. The previous test is pre-filled, so you only change what moved.
Do I have to set up a schedule before I can log?
No. Logging works immediately. Reminders are optional and can be added per tank whenever you decide what cadence the tank needs.
What does the Today screen actually show?
Tanks with work due or overdue, plus any reading outside the range you set for that tank. With Pro, the All Tanks overview ranks every tank by urgency, so the tank that needs you is at the top.
Can I fix a wrong entry?
Yes, entries are editable and deletable. The log is a record you keep, not a ledger you are locked into.
Download

Twenty seconds now, or a lost weekend later

Free for one tank. Install it, log one test, and see whether the history is worth keeping.

Download on the App Store Free · No account · Works offline
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