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

I bought this blue lab PH pen to get a more accurate reading than the solution PH test kit can do. (Place 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 always gives the same readings, but this PH pen seems to have a mind of its own, the 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 that I should be getting very similar readings from feed to feed). So I decided to hesitate and bought some more calibration solution. Seems to help, 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!