API Calcium Test Kit — Aquarium Colorimetric Precision Test - API

API Calcium Test Kit — colorimetric liquid test for aquariums

The API Calcium Test Kit is a liquid-reagent test kit with a colour chart, the reference method for entry- and mid-range aquarium keepers. Compared to test strips, the colorimetric liquid method delivers better accuracy and reproducibility — you read the result on the laminated chart holding the test tube against a white background.

In practical use, this kit lets you monitor calcium in marine reef aquariums (target 420-440 ppm). Reef target 420-440 ppm.

What this kit brings

• Colorimetric liquid method — more accurate than strips.
• Measurement range: 20 ppm increments, reef range 300-500 ppm.
• Number of tests: 50 tests per kit.
• Laminated colour chart included — stable reading over time.
• Test tube and reagents included, FR/EN instructions.

How to use

• Draw a water sample into the test tube (typical 5 ml).
• Add the specified number of reagent drops.
• Agitate and wait per the datasheet.
• Compare against the laminated chart against a white background under daylight.

Specifications

• Parameter: Calcium Test Kit
• Range: 20 ppm increments, reef range 300-500 ppm
• Number of tests: 50 tests per kit
• Method: colorimetric liquid
• Compatibility: freshwater or marine per model

Why get this test from ReefSolution

• API Freshwater Master Test Kit — 5 essential parameters in a single kit for freshwater keepers.
• API 5-in-1 Test Strips — quick 5-parameter check between liquid tests.
• Salifert KH / Alkalinity Test Kit — for a more precise test on SPS reef aquariums.
• Hanna Checker HC HI772 dKH — digital colorimeter for maximum precision on reef KH.

Frequently asked questions

How many tests does an API Calcium Test Kit kit provide?

50 tests per kit — a typical 6-month to 2-year cycle depending on how often you monitor.

Is the API Calcium Test Kit more accurate than a test strip?

Yes — the colorimetric liquid method delivers better accuracy and reproducibility than strips, while staying more economical than a Salifert kit or a Hanna Checker.

Does this kit work on marine tanks or only freshwater?

Depends on the model: kits marked "FW/SW" cover both; "Freshwater" kits are for freshwater only; for reef SPS precision, pick a Salifert or Hanna Checker.