🐠 Free tool · saved in your browser
Reef parameter tracker
Log your reef's water parameters over time and watch the trends. It's the digital version of our printable log — enter your readings, and they're saved right here in your browser(no account, nothing uploaded). Trends catch a slow drift long before it becomes a problem.
| Date | Salinity | Temp | Alk | Ca | Mg | NO₃ | PO₄ | Notes | |
|---|---|---|---|---|---|---|---|---|---|
| No readings yet — add your first above. | |||||||||
- Salinity: 33–35 ppt (SG ≈1.0264 at 25 °C)
- Temperature: 76–82 °F (24.5–27.8 °C) — stable
- Alkalinity: 8–11 dKH (SPS often 7–8) — kept STABLE
- Calcium: 400–450 ppm
- Magnesium: 1300–1400 ppm
- Nitrate: 2–15 ppm — low, but NOT zero
- Phosphate: 0.03–0.10 ppm — low, but NOT zero
Stability beats a perfect number — see the full parameter chart and water chemistry guide.
Quick answers
Where is my reef log data stored?
Only in your own browser (via localStorage). Nothing is uploaded, there is no account, and we never see your readings. The trade-off is that your log lives on this device and browser - clearing your browser data will erase it, so use the print button to keep a copy.
What should I log, and how often?
For a reef, the useful set is salinity, temperature, alkalinity, calcium, magnesium, nitrate and phosphate, plus a note for dosing or water changes. A fish-only or soft-coral tank can log less. Weekly is a sensible default; test more often when you are dialling in dosing or chasing a problem.
What are the target values?
The targets shown come straight from our sourced parameter chart - roughly salinity 35 ppt, alkalinity 8 to 11 dKH, calcium 400 to 450 ppm, magnesium 1300 to 1400 ppm, and nitrate and phosphate low but not zero. Remember stability matters more than hitting an exact number, especially for alkalinity.
Why track parameters over time?
Because trends catch problems before they become crashes. A slow alkalinity drift or a nitrate creeping up is obvious in a log long before it stresses your corals. Logging turns "I think it was fine last week" into data you can actually act on.