The original Hanna Halo wireless pH meter is one of the best standalone pH testers we’ve ever used so naturally, Hanna went and made it even better with the Halo 2. The Halo 2 has all the same features of the original wireless pH meter but this new version also has a built-in screen, so pairing it up to your phone is optional to make at a glance measurements of pH.
You’d think that having to pair up a pH pen to a separate app would put a speed bump into the process of measuring pH but the Halo and Halo 2 connect to the Hanna Lab app pretty much as fast as you click through the connection settings. Since there’s only one button on the outside of the Halo 2, and one secondary button inside the battery cover, the bluetooth connection is helpful for accessing a load of extra features such as – most importantly – the calibration settings with all the data points and time that the calibration was last performed.
One of the things we love about the Halo 2 is that it’s one of the very few handheld units with a built-in screen that reports pH to two decimal places, giving users a much greater resolution for reading pH and which direction it’s trending. Even if you already have some kind of monitor or controller we’ve always appreciated having a separate pH meter to double check the calibration of pH probes that are ‘installed’ in the aquarium system without having to remove them for verification of accuracy.
Normally you’d want to recalibrate any pH meter at least once a year and the Halo 2 will remind you when it’s past its calibration but in our experience the Halo pH probe can easily hold a great precision for over a year! Even after more than 12 months the pH measurement remained very accurate and recalibration wouldn’t correct a pH deviation more than 0.05 pH units.
This reliability of pH measurement is due to Hanna making their own high quality pH electrode with built-in temperature sensor for automatic temperature compensation (ATC) for the most accurate pH reading possible. As an added bonus Hanna was able to make the Halo 2 IP65 water and dust resistance so there’s little chance of ruining this meter in a hot and humid aquarium working environment.
To our surprise Hanna was able to price the Halo 2 wireless pH meter at a very affordable $115 which is sixty dollars cheaper than the original Halo even though the second generation has a built in screen for displaying the current pH reading, and it comes with several sachets of calibration solution, cleaning solution, and a small bottle of storage solution. Any old pH pen will work if you’re simply looking for a simple pH pen to tell you whether a solution is basic or alkaline but if you want a really accurate reading and the extra additional features that comes from connecting the pH meter to your phone, the Halo 2 from Hanna is hands down the best wireless pH meter we’ve ever used.