Always get accurate results for your saltwater aquarium with our handheld colorimeter.
The Hanna Checker®HC calcium colorimeter fills the gap between calcium test kits and advanced instrumentation.
Standard test kits have limited accuracy as they depend on the human eye to determine colors. The HI758 eliminates the trouble of matching to a color chart by providing a direct saltwater calcium result in ppm Ca2+.
The HI758 Checker® HC provides a simple, accurate and cost-effective way to measure calcium. Required for the development of calcium carbonate skeletons of coral reefs, calcium is a crucial component of marine waters. Designed as a more accurate alternative to chemical test kits, the HI758 provides quick, accurate results in a few easy steps.
The HI758 Marine Calcium Checker HC® uses a 100 to 1 dilution for analysis and thus requires deionized or distilled water absent of calcium to function correctly. 
Calcium can be found in many freshwater sources and this any amount present in the water used at the C1 phase can cause false high readings. In addition, many hobby grade reverse osmosis deionized water systems may not adequately remove calcium. This can vary based on the types of filters used, their effectiveness and frequency of replacement. 
We recommend using deionized water with low conductivity or pure vapor distilled water commonly found in most pharmacies.
Never use tap water to clean your cuvettes. This is especially important for the HI758 Marine Calcium Checker as calcium is commonly present in tap water and residual amounts present in the cuvette will elevate results produced by the Checker.
Our HI98703-50 Cuvette Cleaning Solution ensures the glass cuvette used for colorimetric measurements remains clean and free from imperfections.
Sepcifications:
Range : 200 to 600 ppm 
Resolution : 1 ppm
Accuracy @ 25°C : ± 6 ppm 
Light Source : LED @ 610 nm
Light Detector : silicon photocell
Battery Type : (1) 1.5V AAA
Auto-off : after 10 minutes of non-use
Environment : 0 to 50°C ; RH max 95% non-condensing
Dimensions : 86.0 x 61.0 x 37.5 mm
Weight : 64 g
Calibration Set : HI758-11 Not included
Warranty : 1 year
What's inculded
1x HI758 Checker®HC 
2x sample cuvettes with caps
1x HI-758-25 reagent (25 tests)
1x 100 µL pipette
1x plastic pipette
1x syringe with tip 
1x batteries
1x instructions, and quick start guide.