Review on Boost Hydroponic Growth with PENCON Conductivity Temperature Nutrient System by Robert Rick

The pen is easy to use and can read 500ppm, 700ppm and EC, but you must use the 500ppm mode as the EC mode only reads up to 1 decimal place and uses millisiemens. 500ppm mode reads in increments of 10, which equals 20 EC, making it five times more accurate than EC mode. And then don't forget to count. Why couldn't they read EC to 2 decimal places or just use microsiemens when the meter can measure that? Stupid. Also, it says very clearly that calibration is optional and optional, and I didn't bother finding a solution as mine was new and I've never had a TDS meter before, but this one showed *40%* high of boxes. However, I haven't found it for weeks. Buy a calibration solution before you make a mistake on something important, or buy another meter that reads EC correctly in microsiemens so you don't forget to count and make a mistake on something important.