Bests & Worsts Reviews from Amazon

I bought this blue lab PH pen wanting more accurate readings than what can be provided with the solution PH testing kit. (Add drops to that small clear container, shake to agitate and record color reading) However this PH pen is a joke when it comes to consistency. My $2 testing kit consistently gives the same readings, however this PH pen seems to have a mind of it's own with readings varying day to day with the same solution mixture. (And mind you I start with distilled water and use oral syringes for measuring so I know for a fact I should be getting very similar readings from feed to feed). So I gave it the benefit of the doubt and bought some more calibration solution. Sort of helps but again it seems to only maintain it's baseline for a day before falling out of wack again. For any new growers wondering if this is a worthwhile investment, I'd just pass. Get the small solution based PH testing kit and forget all the calibration and BS that comes along with this product. Cheers to all hope this saves even one person some money!