Review on Arduino-Compatible TDS Meter Probe for Water Quality Monitoring V1 Sensor Module with XH2.54-3Pin Jumper Wire Connector by KEYESTUDIO by David Dortch

They are really inaccurate. I compare it to TDS readings from a portable device and this meter consistently reads twice as much as the meter reads. If the 1024 gauge registers below 500ppm it can't even be used on the simplest leafy greens in a hydroponic system so I've just spent hundreds on a real Atlas Scientific gauge and am hoping it works better. Maybe they can say that hydroponics is not the intended goal, but they still have to be accurate within the intended range and there is no way to calibrate them. It would be much better if there was a potentiometer on it so I could calibrate it or even increase the PPM range to at least 3000. I could adjust the values in the code, that would be easy, but even if I could get 700, if the real value was 2100 and I could divide it by two, the error would be acceptable. Unfortunately, these devices are unacceptable in their current form, although they are cheap, it's a waste of time and money. Maybe I'm missing something. I would because the alternatives aren't cheap.