tds meters

Hello guys, First time posting on the forms after lurking around for a few months. I'm starting to get into aeroponics and EZcloner stuff and I'm having a hard time finding recommendations for EC / PPM monitors. What are you guys using? I'm aware that I will have to keep an eye on water...

well damn!!!! My ph pen dropped into water so I bought a new one....along with a new ppm /EC pen! While making a solution to see how much PPM is in it due to the fact I added alittle CAL/MAG. No calibration pens even though I thought with this new one I'd have to calibrate it. The ppm with...