Matching a color-card test kit reading against shades of pink or purple leaves real room for interpretation - the Hanna HI781 replaces that guesswork with a digital colorimeter reading, no more guessing between shades on a color card.
Why a Digital Colorimeter Beats a Color Card
Color-match test kits ask you to compare a sample against printed or plastic reference shades, which is inherently subjective - lighting, eyesight, and even the age of the reference card all affect the reading. A colorimeter measures light absorbance directly and reports a number.
What the HI781 Offers
- Handheld digital colorimeter for low-range nitrate testing in saltwater aquariums.
- Objective, repeatable readings instead of subjective color matching.
- Simple, consistent testing process that removes reader-to-reader variability.
Keeping It Running
For aquarists running higher-nutrient systems, the High Range Checker Reagents (25 tests) extend testing into elevated nitrate ranges the standard low-range checker isn't built for. The Low Range Checker Reagents (25 tests) restock the HI781's standard testing supply once the included reagents run out.
Setup Tips
- Choose high-range reagents if your tank runs consistently elevated nitrate, such as a fish-only or heavily-stocked system.
- Calibrate the unit periodically per manufacturer instructions to maintain accuracy.
- Store reagents properly to preserve shelf life between tests.
The Hanna Marine Nitrate Checker and reagents are available at Marine Concept Supply - order online or pick up at our shop in Wheeling, IL. Shop the HI781 Checker, High Range Reagents, or Low Range Reagents, and browse more aquarium testing.
