lex0415 said:

EC is not more accurate, EC is converted into ppm using a scale.

It is good to know both because people use both. So knowing what the conversion is will help people understand when someone else uses either measurement.

If anything I would say ppm is more accurate because it uses a smaller unit of measurement, so you have a more precise number when using ppm. You just have to know what scale you are using whether it is .5 or .7.

For example, on the .5 scale, 0.1 EC is 50 ppm. So increments of 0.1 EC is equal to 50 increments of ppm, so since ppm uses a smaller unit of measurement it is technically more accurate.

Click to expand...

airedog said:

You are only as accurate as the resolution of your initial measurement (EC), the rest is just silly math tricks. I had it explained best by an electronics prof this way;

There was a school dance and one of the dances allowed the partners to halve the distance between them by half every 30 seconds. The mathematicians were inconsolable as the halving was mathematically inifinte and there would always be distance between the partners; the engineers were happy though as they'd 'get close enough'. Use a standard and familiarize yourself with the sweet spot for the plants you are growing and be sure to calibrate your meter monthly.

Click to expand...