OK did a little test. Took reading of tap water. I then added a little Big grow at a time. Readings slowly increased up to 950 ppm. Once it went over it started reading 1.05 So I believe that you were correct once it goes over 999 it converts to 10x . So a reading of 1.05 would be 1050 ppm. If this is the case then I’m crazy high at 4.13
Tap water
Increased nutrients
