To keep your saltwater reef aquarium healthy, you want to maintain optimal calcium levels to ensure the health of your fish and corals. An optimal calcium range (350-450 ppm) is vital for coral calcification and skeletal formation. Calcium should be checked weekly at minimum, and every time you add or remove any organisms from your tank. The easy-to-use Hanna Marine Calcium Checker HC - HI758 generates accurate, digital readouts in parts-per-million (ppm) versus trying to judge traditional calcium test kit color changes.

In addition to being easy and accurate, the full line of Hanna Marine Checkers eliminate the hassle of always having to buy new test kits. When you run low on the supplied HI758-26 reagent (25 tests per bottle), just purchase a refill pack and you are back to testing in no time.

Everything You Need to Start Testing

Our marine calcium checker is supplied as a complete test kit and retails for $49. The kit includes:

  • Hanna Marine Calcium Checker HC - HI758
  • Two sample cuvettes with caps
  • Reagents for 25 tests
  • Plastic dropper
  • One 1mL syringe with tips
  • One 0.1mL mechanical pipette with tips
  • One AAA Battery
  • Water resistant case to store all testing items
  • The HI758 instruction manual with reference guide. The reference guide includes the testing instructions and tips for accurate measurement. It’s the perfect companion to have while you are performing measurements.

How to Test:

The Hanna Marine Calcium Checker is designed to make testing quick and easy.

  1. Press the button to power the meter on. When Add C1 appears on the screen, you are ready to begin testing.
  2. the 1mL syringe, add 1mL of reagent A to the clean cuvette. Then, using the dropper, fill the cuvette to the 10mL mark with deionized water. (Distilled water is also acceptable.) Once the reagent and water are added, invert the cuvette five times to mix.
  3. Using a microfiber cloth, wipe the cuvette to remove any oils or fingerprints from the glass. Then place the cuvette into the checker and close the lid, making sure it is completely closed. It is important to make sure that the lid is completely closed for an accurate reading.
  4. Press the button. Once the screen reads Add C2, remove the cuvette from the meter.
  5. Add 0.1mL of sample. For best accuracy, use the supplied 0.1mL pipette.
  6. Once the sample is added, add one packet of reagent B to the sample, then cap the cuvette and shake vigorously for 15 seconds. Wait 15 additional seconds for the bubbles to dissipate.
  7. Wipe the cuvette of any oils and fingerprints and place back into the meter.
  8. Press the button; the meter will display the concentration of calcium in ppm.

Hanna Tip: To use the Hanna Instruments Micropipette, first attach the pipette tip. Push the button to the first stop, and then immerse the tip into the sample. Slowly release the button to its original position. Then, wait two seconds to catch any drops before dispensing the sample into the cuvette to the second stop.