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dKH Alkalinity Checker® and Related Products

  • Get accurate results for your saltwater aquarium with our simple handheld colorimeter digital test kit.  The HI772 dKH Alkalinity Checker®HC is our most popular selling aquarium product. Our alkalinity colorimeter bridges the gap between alkalinity test kits and advanced instrumentation. Standard test kits have limited accuracy since they rely upon the human eye to match colors. Our handheld colorimeter eliminates the hassle of matching to a color chart by providing a direct saltwater alkalinity result in dKH units.

    ·       Remove the human error from your testing

    ·       No need to count drop or titrate your sample

    ·       Detects color changes your eye cannot

    ·       No calibration required

    ·       Get east, quick and consistent results

    ·       Accurate and affordable

    ·       Cost efficient: Once you purchase the Checker, reagents are sold separately saving money long term



    The HI772 Checker®HC (Handheld Colorimeter) provides a simple, accurate, and cost-effective way to measure alkalinity in degrees of carbonate hardness, commonly abbreviated as dKH. Critical to marine environments, alkalinity not only provides the carbonate ion required for calcium carbonate skeletal regeneration of coral reefs, but it also acts as a pH buffer against large changes in acidity. Designed as a more accurate alternative to chemical test kits, the HI772 provides quick, accurate results in a few easy steps.

    Features at-a-glance:

           Easier to use and more accurate than chemical test kits

           Most popular reef aquarium product

           About one minute to preform a test

           Comes with 25 tests; HI772-26 refill




    0.0 to 20.0 dKH


    0.1 dKH

    Accuracy @ 25°C/77°F

    ±0.3 dKH ±5% of reading

    Light Source

    LED @ 610 nm

    Light Detector

    silicon photocell


    colorimetric method


    0 to 50°C (32 to 122°F); RH max 95% non-condensing

    Battery Type

    (1) 1.5V AAA


    after ten minutes of non-use


    86.0 mm x 61.0 mm x 37.5 mm (3.4" x 2.4" x 1.5")


    64 g (2.25 oz.)

    Ordering Information

    HI772 Checker® is supplied with (2) sample cuvettes with caps, alkalinity reagent starter kit for 25 tests (1 bottle of alkalinity reagent), (1) 1 ml syringe and tip, ­­­ battery, instructions, and quick start guide.


    1 year limited warranty