Comparison
Hanna HI772 Checker vs Salifert KH Profi-Test
Side-by-side comparison of the Hanna HI772 marine alkalinity checker and the Salifert KH/Alkalinity Profi-Test. Real precision specs, per-test cost, and a hobbyist verdict on which one to trust when they disagree.
The contenders
Side A
Hanna HI772 Checker
Colorimetric digital
Side B
Salifert KH Profi-Test
Titration kit
Spec-by-spec
| Spec | Hanna HI772 Checker | Salifert KH Profi-Test |
|---|---|---|
Test method | Colorimetric (LED + photocell) | Acid titration with colour indicator |
Range source | 0.0 – 20.0 dKH | 0 – ~20 dKH (depends on sample size) |
Resolution source | 0.1 dKH | 0.1 dKH (with 2 mL sample) |
Stated precision | ±0.3 dKH ±5% of reading | Manufacturer publishes no formal precision figure |
Time per test | ~3 minutes including the 2:45 reaction wait | ~2 minutes (titrate to colour change) |
Cost per test | ~$0.60 with HI772-26 reagents (25 tests for ~$15) | ~$0.20 (100 tests per $14 kit when 2 mL sample) |
Sample size required | 10 mL exact | 2 mL or 4 mL (4 mL gives finer resolution) |
Calibration | None — uses internal CAL standard each run | User calibrates against fresh saltwater |
Common failure mode | Old or contaminated reagents read low by 0.5–1.5 dKH | Colour endpoint subjective; partial-syringe errors of 0.1–0.3 dKH |
Wet reagent shelf life | 12 months from manufacture | Date stamped — typically 24 months from manufacture |
Which one for which situation
New reefer who tests weekly
Pick: Salifert KH Profi-Test
Salifert is cheaper per test, doesn't need batteries, and the colour endpoint is forgiving once you've done a dozen tests. The Hanna's reagent shelf life often expires before a casual tester runs through the bottle.
Daily-testing SPS tank chasing 8.0 dKH ±0.2
Pick: Hanna HI772 Checker
Digital read removes user error from the loop, and the 3-minute total time matters when you test every day. Buy reagents in 75-test packs and rotate the lot stamp.
Cross-checking before a big dose
Pick: Either works
Run both and reconcile. If they disagree by more than 0.5 dKH, mix fresh saltwater at known SG and re-test — whichever matches the salt manufacturer's published alkalinity is the kit to trust this week.
Travelling reefer / vacation kit
Pick: Salifert KH Profi-Test
Salifert is a sealed dropper bottle and a tiny syringe — no electronics to fail in a checked bag.
Where to buy
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Related calculators & references
Sources & references
- 01Hanna Instruments — HI772 product pagehttps://hannainst.com/marine-alkalinity-dkh-checkerr-hc-hi772.html
- 02Bulk Reef Supply — Salifert KH/Alkhttps://www.bulkreefsupply.com/salifert-kh-alkalinity-aquarium-test-kit.html
- 03Randy Holmes-Farley — Reef alk recipe primerhttps://reefs.com/magazine/aquarium-chemistry-a-homemade-two-part-calcium-and-alkalinity-additive-system/
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