With 5 tanks full of different water critters i am always checking PH among other things.This Digital tester is faster than my chemical test and seems to be just as accurate. Easay to calibrate with enclosed chemicals. The TDS meter is helpful too.If the TDS is on the higer sied i know i need a water change sooner than expected or have filter issues. The temp gauge helps me monitor both the cold water and warm water tanks. Both are easy to read and have quick results. A cap for on the end for strage. Each in a case too. #Rankboosterreview #Sponsored #SunGrow https://www.amazon.com/Digital-TDS-Meter-Set-SunGrow/dp/B06XSL8LX3