No offense but my father is a chemist and my step-father is a botanist and my younger brother is a pharmacist and you have your terms wrong...
And waht you absorbed there traing and education by assmossis by sitting on the same toilet seeat. What education do you have. Did you even finish high school or are you still in high school?
Most posters to growing forums list their tap water and RO filter water as TDS in ppm a not an EC measurement. I mistakenly thought that is what you were meaning and simply though you were meaning that. Many/most hobby grade meters are TDS meter and do not even display EC, yet alone show units for the measurement of EC if shown. As a matter of fact most people, even scientists (I am a resaerch scientist) do not even use ms/cm units when referring to EC when talking to lay people. I think I have seen it used maybe one other time in this forum but not in casual sense as you did.
You nearly always need your EC above 1 generally you need it at almost 2 (measured in miliSiemens which is what I assume you are talking about), to keep things simple I didn't note that my "PPM" TDS meter measures in microsiemen (not miliSiemens), and as I'm sure you understand EC stands for Electrical Conductivity and is measured in mS/cm or miliSiemens per centimeter.
Wow, that is news to me. I always use my nutrients at around 600 or lower and I grow A LOT, and have done so for over 35 years. My larger tube and chamber misting aero is an even lower TDS. I do not expect to ever need a TFS higher than 450 in my air atomized chambers just being set up.
TDS stands for Total Dissolved Solids and is measured in ppm or parts per million. TDS is acquired by taking the EC value and performing a calculation to determine the TDS value. Because TDS is actually a calculation it is really only a guess at what the nutrient concentration is. On top of that, there are three different conversion factors to determine TDS and different manufacturers use different conversion factors. In other words you could test the same solution with two different meters and get two totally different readings. But the EC is read the same by all meters the only difference is the conversion factor.
Dude I have given the same explanation only better many times. Get over it and move on.
When you talk about PPM you are NOT talking about EC you are talking about a conversion factor which is used by most PPM meters that take the EC in mili or mico and convert it to PPM using either the NaCl Conversion (.4) or the 442 Conversion (.7) conversion.
Your still jabbering?
An EC of 2.0 (again using miliSiemens) or 2000 using (microSiemens) is 1000 ppm (again using the NaCl Conversion) or 1400 PPM (using the 442 Conversion).
When you talk about PPM in the future you need to specify which conversion factor you are talking about... because PPM ## is useless with out this info!