TDS PPM PPT / EC doubts.

Hello guys! im using a simple DRWC system for my plant, and i few months ago i had a lot of problems measuring the "EC" of my solution because a lack of knowledge about that, until today i was using a really cheap EC metter ( the first one on the photos ), the measure of that metter is on "PPM" parts per million, so i was using from 300 PPM to 1000 APROX, based on the table on the second image, now i have a new EC metter ( Milwaukee EC60 ), i can use it on PPT or EC, of course i dont want to mess up my plant, so Its better to use it on PPT, or can i use it on EC, as far as i can see the EC its universal, but the PPM and PPT of course are not the same number, what would be the better ?


Thanks in advance.

Technically they're all reading EC anyway. The ppm reading is simply a conversion of EC based on a standard solution either 500 scale or 700 scale. I personally like to track my PPM on the 700 scale as I see changes to nutrient strength more accurately. Lets me more easily see what my plants are eating.

I've used one of those HM ppm meters for going on 17 years now. Still accurate. EC, ppm, tds, your plant really doesn't care unless you're messing it up. What's important is consistency of readings and your paying attention to how it's affecting your plant.

Make sense?