Parameters
Log salinity, temperature, alkalinity, calcium, magnesium, nitrate, and phosphate with the kit method beside each number. A weekly reef tank test log is boring on purpose—that is what makes drift readable.
Sea Life Planet · Reef parameters
Test first. Change slowly.
A weekly log and conservative ranges before you dose.
Here is how to log reef tank parameters safely: write the week’s numbers, read common target ranges, follow a fixed test order, and only then decide whether a small correction—or another retest—is the next move.
Weekly test-order table
Run one session in this order. Tap a step to highlight the matching job card below. Ranges are labelled common—they are hobby reference bands, not guaranteed outcomes for any livestock.
| Order | What to log | Common target range | Job focus |
|---|---|---|---|
| 1 | Date, sample point, kit method | common Same window each week | Parameters |
| 2 | Salinity (SG or ppt) + instrument | common ~1.024–1.026 SG · ≈32–35 ppt | Salinity |
| 3 | Temperature | common ~76–78°F steady | Parameters |
| 4 | Alkalinity (dKH) | common ~7.5–9.0 dKH | Testing order |
| 5 | Calcium, then magnesium | common Ca ~400–450 ppm · Mg ~1250–1400 ppm | Testing order |
| 6 | Nitrate and phosphate | common NO₃ ~2–10 ppm · PO₄ ~0.02–0.08 ppm | Parameters |
| 7 | Actions taken (or “none”) | assumption One variable · multi-day pace | Dosing assumptions |
| 8 | Retest due | rule Pause before any large swing | Pause-and-retest |
Common target ranges are reference bands many mixed-reef keepers discuss. They are not livestock guarantees, species prescriptions, or a reason to slam a value into the middle of a band in one day.
Five jobs before you correct the tank
Cards, not a tutorial. Use them with the table above when a reading looks off.
Testing order
Calibrate, then anchors (salinity and temperature), then alkalinity, then major ions, then nutrients. Order cuts false emergencies from evaporation, top-off mistakes, and unsettled samples.
Dosing assumptions
Reef tank dosing calculator assumptions here are labelled pacing defaults: verify twice, keep salinity stable first, change one variable when you can, and split large gaps across days with a written retest. Not a prescription to dose.
Salinity
Pick one primary unit. Salinity conversion for reef keepers stays in the journal only to translate a second instrument—log conflicts instead of blending SG and ppt into one “average.”
Pause-and-retest
A safe change rate for reef parameters starts with stop: repeat the test, confirm anchors, compare the last two weekly rows, then choose at most one small action—or none. Surprise numbers are often method, not catastrophe.
Why keepers trust these notes
Written from tank time
Sea Life Planet is an independent fishkeeping guide publication from Hektor Jorgo and Chris Brady. Notes come from FOWLR and mixed-reef systems we actually run—not packaging copy.
Combinations that fail
We publish the downside: stacking additives, large water changes, media swaps, and new foods in one evening hides which move mattered. The log keeps events separable.
Corrections stay a priority
310+ expert guides, free always. When a method or range needs an update, we fix the page—husbandry first, no manufactured urgency.
FAQ
How often should I fill the weekly reef tank test log?
Once a week in the same lights-on window is enough for most mixed reefs. A complete row beats scattered mid-week scraps you cannot compare.
Are reef tank parameter target ranges mandatory?
No. Bands on this page are common targets, labelled as such—not guarantees. Keep any tighter personal band in your notes and refuse same-day leaps either way.
What counts as a safe change rate for reef parameters?
Conservative pacing: second test first, salinity stable, one variable when possible, multi-day splits with a written retest. We do not endorse large same-day swings.
Is this veterinary advice?
No. This is husbandry and record-keeping for saltwater keepers. It does not diagnose animals or prescribe medication. For emergencies, contact a qualified aquatic veterinarian.
Where do species and equipment guides live?
Open the matching guide on Sea Life Planet—saltwater hub, corals and invertebrates, or equipment reviews—when your log shows a pattern you want to understand more deeply.
Sea Life Planet
Keep the log conservative. Open the guide that matches the tank.
Practical aquarium care guides backed by real tank experience. Browse saltwater husbandry, coral notes, or equipment reviews when the journal points to a deeper read—not a same-day chemistry sprint.