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

I bought this blue lab PH pen to get more accurate readings than the solution pH test kit comes with can become. (Put drops in this small clear container, shake to mix and record the color reading). However, this PH pen is a joke when it comes to consistency. My $2 test kit gives the same readings consistently, but this PH pen seems to have a mind of its own as readings change from day to day with the same mix of dilutions. (And note, I'm starting with distilled water and using oral syringes for measuring, so I know for sure I should be getting very similar readings from feed to feed). So, when in doubt, I agreed with him and bought some more calibration solution. Seems to be helping, but then again it only seems to maintain a baseline for a day before failing again. For any new growers wondering if this is worth the investment, I would simply say no. Get a small solution based PH test kit and forget about all the calibrations and BS that come with this product. Hey everyone, I hope this saves at least one person some money!