Hanna Instruments makes the line of "Checker" colorimeters - handheld digital test instruments that read alkalinity, calcium, magnesium, phosphate, nitrate, and pH from a small water sample with a reagent. Significantly more accurate than titration test kits and faster to run.

Known for

Hanna Alkalinity Checker (HI772)

The single most-used reef chemistry tester. Reads alkalinity in dKH or ppm to 2 decimals in 30 seconds.

Calcium Checker (HI758) + Phosphate (HI774)

Calcium reads in ppm to whole numbers. Phosphate ULR (HI774) reads to 0.001 ppm - critical for SPS reefs.

edge pH meter

Higher-accuracy bench pH meter with replaceable probe. Better than a typical pH probe for one-off accurate pH readings.

Pros and cons

Pros
  • Significantly more accurate than titration kits for the parameters they cover
  • Fast - 30 seconds per test vs 5-10 minutes for titration
  • Reagent costs are reasonable in pre-measured packets
Cons
  • Each tester reads only one parameter - need 3-5 testers to cover full reef chemistry
  • Reagents have a 12-18 month shelf life

Common competitors

Salifert (titration) · Red Sea (titration) · Triton ICP · Apex Trident