No entries yet. Fill the form above and the first one lands here.
This is the paper logbook, rebuilt as a page. Type the reading, hit save, and the entry is listed newest first with the rest of the week. Edit a typo, delete a duplicate, and export the whole thing as CSV when you want a copy that survives a cleared browser.
What to record, and how often
Four numbers cover almost every freshwater problem: pH, ammonia, nitrite and nitrate. Ammonia and nitrite should read zero in a cycled tank, so they are the fastest warning you have. pH drifts slowly, which only becomes visible when the entries are dated and kept together.
- Test ammonia and nitrite whenever something looks wrong — a new fish, a filter clean, a dead snail. Any reading above zero is the whole diagnosis.
- Test nitrate weekly, before the water change, so the number is comparable across weeks rather than drifting with the schedule.
- Log the water change in the same entry as the test. A reading without the maintenance that produced it cannot tell you whether the interval is right.
- Use the notes field for what the kit cannot measure: appetite, behaviour, new plants, a cloudy patch, the filter media you swapped.
Why there is no sign-up
Every browser log with an account needs a server, and a server means a copy of your tank history, a password to reset, a database to back up and a breach to disclose. The app skips all of it by keeping the log on the device; this page does the same by keeping it in the browser. There is nothing to sign into because there is nowhere for the data to go.
Entries are written to localStorage for this site. They survive a reload, a restart and a week of not visiting — but not “clear website data”, private browsing, or a different browser on the same machine. If the log matters, export the CSV; it takes one click.
Reading the numbers together
| Reading | Where it should sit | What a miss usually means |
|---|---|---|
| Ammonia (NH₃) | 0 ppm | The cycle is overwhelmed — feed less, change water, do not add fish. |
| Nitrite (NO₂) | 0 ppm | The second bacteria stage is lagging behind the first. |
| Nitrate (NO₃) | Under 20 ppm before a change | Change more, or more often — the interval is too long. |
| pH | Stable, whatever the tank runs at | A moving pH matters more than an unusual one. |
A single row tells you what the tank is doing now; four dated rows tell you what it is trending towards. If a nitrate reading looks high, the water change calculator turns it into a percentage, and if you do not know the real water volume yet, start with the volume calculator. When you want reminders, trends and more than one tank, that is what the app is for.
