Hanna Marine phosphate - ultra low range Checker HC® colorimeter: Range 0.00 to 0.60 ppm

The Hanna Phosphate Ultra Low Range (0.00 to 0.90 ppm) Checker® bridges the gap between simple chemical test kits and professional instrumentation. Chemical test kits have limited accuracy and resolution since they rely upon the human eye to discern differences in color. Professional instrumentation incorporates a light source such as an LED or tungsten lamp with a filter and a light-sensing detector to precisely determine ion concentration. Professional instrumentation offers greater resolution and accuracy but can cost hundreds of dollars. The Hanna Phosphate Ultra Low-Range Checker® uses a fixed wavelength LED and silicon photo detector to provide the accuracy of professional instrumentation at the affordable price of a chemical test kit.

  • Compact, Portable Design
  • Built-in Timer
  • One-Button Operation

The HI774 Checker® HC (Handheld Colorimeter) provides a simple, accurate and cost-effective way to measure phosphate in marine systems including coral reef tanks. Phosphate is an important parameter to measure in aquaculture and aquariums; levels that are too high can lead to extensive algae growth, depleted dissolved oxygen levels, and ultimately can be fatal to many types of fish and aquatic life. Designed as a more accurate alternative to chemical test kits, the HI774 provides quick, accurate results. For those that would like measure phosphate as phosphorous we off the HI736 Phosphorous Checker® HC. Alternatively, to determine the fraction of phosphorous (PO4-P) there is in phosphate (PO43-) the phosphate reading is multiplied by 0.3261. A 0.50 ppm phosphate reading is equal to 0.163 ppm or 163 ppb phosphorous.

How to use Hanna Checker Handheld Colorimeter

Features at a Glance

Pre-mixed Chemistry

  • Reagents are pre-measured packets that are added to the sample to take a reading.

Colorimetric Readings

  • Using an LED at a specific wavelength and silicon photo detector the HI774 can perform a precise reading of the color change in the sample based on the phosphate concentration.

Checker HC Calibration Standards

  • The HI774-11 CAL-Check standards can be purchased separately and are used to check the performance of the meter to ensure confidence that the meter is working properly.


Automatic Shut-off

  • The meter is programmed to turn off after seven minutes of non-use or two minutes after taking a reading.

Long Battery Life

  • The phosphate ULR Checker has an exceptional battery life with a fresh battery lasting for a minimum of 5000 measurements.

Plastic Carrying Case

  • The 774 is supplied complete with meter and reagents for 10 tests that are packaged in a durable plastic carrying case.


  • Laboratory grade measurements at a cost of a chemical test kit.
Product Name Marine phosphate - ultra low range Checker HC® colorimeter: Range 0.00 to 0.60 ppm
Phosphate Range 0.00 to 0.90 ppm
Phosphate Resolution 0.01 ppm
Phosphate Accuracy +/- 0.02 ppm +/- 5% of reading
Phosphate Method adaptation of the Standard Methods for the Examination of Water and Wastewater, 20th edition, Ascorbic-Acid method. The reaction between phosphate and the reagent causes a blue tint in the sample.
Photometer/Colorimeter Light Source LED @ 525 nm
Photometer/Colorimeter Light Detector silicon photocell
Battery Type/Life (1) 1.5V AAA
Automatic Shut-Off after seven minutes of non-use and two minutes after taking a reading
Environment 0 to 50°C (32 to 122°F); RH max 95% non-condensing
Weight 64 g (2.25 oz.)
Dimensions 86.0mm x 61mm x 37.5mm (3.4" x 2.4" x 1.5”)
Ordering Information HI774 Checker® is supplied with (2) sample cuvettes with caps, phosphate ULR reagent for 10 tests, battery, instructions and quick start guide

Hanna Marine phosphate – ultra low range Checker HC®