Coralkinhonest saltwater & reef care

🧪 Free tool · straight from our parameter chart

What do my water test results mean?

You tested your water — now what? Enter any readings you have and we'll tell you whether each ison target, a little off, or a problem, and the safe next step. Every range comes straight from our fact-checked parameter chart, so this can never contradict the guide. Leave anything you didn't test blank.

target 33–35 ppt (SG ≈1.0264 at 25 °C)
ppt
target 76–82 °F (24.5–27.8 °C) — stable
°F
target 8.1–8.4
target 8–11 dKH (SPS often 7–8) — kept STABLE
dKH
target 400–450 ppm
ppm
target 1300–1400 ppm
ppm
target 2–15 ppm — low, but NOT zero
ppm
target 0.03–0.10 ppm — low, but NOT zero
ppm
target 0 — undetectable
ppm
target 0 — undetectable
ppm
Stability beats a perfect number. A steady reading a touch outside "ideal" is safer than one that swings into range and back. If a parameter is off, fix it slowly. Full context on every number is in the parameter target chart, and you can log readings over time with the parameter tracker.

Quick answers

What do my reef tank test results mean?

Enter each reading and this tool checks it against the reef-standard target range, tells you whether it's on target, a little off, or a problem, and gives the safe next step. Every range comes straight from our sourced parameter chart. Remember: stability matters more than hitting an exact number, especially for alkalinity.

My nitrate/phosphate isn't zero — is that bad?

No — the modern reef target is low but NOT zero. Truly zero nitrate and phosphate starves corals, pales SPS, and triggers dinoflagellates. Aim for roughly nitrate 2–15 ppm and phosphate 0.03–0.10 ppm, not undetectable.

Which parameter matters most?

For a reef, alkalinity stability is the one that most often makes or breaks corals — a swing does more harm than a slightly "wrong" steady number. Salinity, temperature, ammonia and nitrite are the make-or-break basics for keeping anything alive. Calcium and magnesium matter once you keep stony corals.

How often should I test my reef?

While a tank is new or you're dialling in dosing, test the key parameters a couple of times a week. An established, stable reef can settle into weekly for the core numbers. Log them over time so you catch a slow drift before it becomes a crash — our parameter tracker does exactly that.

Off on alkalinity, calcium or magnesium? The dosing calculatorworks out exactly how much to add. Salinity reading looks odd? Try the salinity converter.