Review on Bluelab PENPH pH Pen: Accurate Water Digital Meter with Dual Probe for Hydroponic System and Indoor Plant Grow, White by Anna Lopez

After reading the reviews I was afraid to buy another one and of course I sold the two tier pen! The box was already opened and the pen looked used. There was a layer of hardened material on top of the sensor and after washing and calibrating the stylus with what was provided, it doesn't read exactly like my blue pens I've had in the past. That's of a few decimal places and it's driving me crazy. Very disappointed in this purchase, knowing it's something that is drying up and not working properly they should throw it away before selling rather than selling a counter that has been sitting on a shelf for centuries.