My original goal with this video was to use up all the reagent in one day… Needless to say, that did not happen. I probably performed around 50 tests, and didn’t even go through half! Crazy how many tests this comes with, especially considering the Hanna Phosphate Checker only comes with six!
Another quality product from Hanna to be sure, I just wish it had a bit more accuracy. A plus or minus 0.2 is quite a lot when talking about pH. But is this more accurate than any other commercially available hobbyist level test kit? Of course!
Table of Contents
I) Hanna pH Checker

HI780 Marine pH Checker HC Handheld Colorimeter – Hanna Instruments
The HI780 pH Checker HC by Hanna Instruments is a simple, accurate, and cost effective way to measure pH in seawater. Designed as a more convenient alternative to chemical test kits, this handheld colorimeter provides quick, accurate pH testing results.
Why are pH levels important?
pH levels affect marine life growth, reproduction, and communication. In the context of corals, incorrect pH levels can inhibit skeleton building and limit overall growth.
Features:
- Great for saltwater aquariums and marine environmental testing
- Easier to use and more accurate than chemical test kits
- Dedicated to a single parameter
- Simple one-button operation
- Digital read out for added convenience
- Compact size for easy travel and storage
II) Specifications

Specifications | |
---|---|
Range | 6.3 to 8.6 pH |
Resolution | 0.1 pH |
Accuracy @ 25°C/77°F | ±0.2 pH |
Light Source | LED @525 nm |
Light Detector | Silicon photocell |
Method | Colorimetric adaptation of phenol red method |
Auto-off | After ten minutes of non-use |
Environment | 0 to 50°C (32 to 122°F); RH max 95% non-condensing |
Battery Type | (1) 1.5V AAA |