EC to ppm conversion

[urbanite420]

Hi All, Thought I would ask what conductivity/EC/PPM conversion is most used by my fellow farmers. I prefer to use EC, but I notice that many farmers use ppm so "The communication problem" persists between peeps like me and lots of other farmers.

(from 420 mag)
So again, the problem is that different ppm pen manufacturers use different conversion factors to calculate the ppm they display. All ppm (TDS, Total Dissolved Solids) pens actually measure in EC or CF and run a conversion program to display the reading in ppm's.

There are three conversion factors which various manufacturers use for displaying ppm's...

USA 1 ms/cm (EC 1.0 or CF 10) = 500 ppm
European 1 ms/cm (EC 1.0 or CF 10) = 640 ppm
Australian 1 ms/cm (EC 1.0 or CF 10) = 700 ppm

For example,
Hanna, Milwaukee 1 ms/cm (EC 1.0 or CF 10) = 500 ppm
Eutech 1 ms/cm (EC 1.0 or CF 10) = 640 ppm
Truncheon 1 ms/cm (EC 1.0 or CF 10) = 700 ppm

 

[ilikepot]

Most Hanna PPM meters use the 442 conversion. There are a couple that you can adjust the conversion factor from .5 to .7. Most Nutes use the NaCI conversion. here is how it breaks down:
442 conversion is approximately 700 x EC in miliSiemens (mS). Then there is the NaCl conversion (sodium chloride) which others say is the closest thing to a hydroponic solution. The NaCl conversion is approximately 500 x EC in miliSiemens (mS).

So IMHO just follow the driections on the nutes you are useing and don't even bother with the PPM meter or get an EC meter and do the conversion your self. OR make sure what meter you are getting. MOST meters useing the 442 comversion top out at 2000 ppm that's like1480'ish on the NaCI scale. So if you are ever going to push the nutes to 15000 NaCI in like weeks 3, 4, 5, amd 6 of flower then what is the point in having one of the 442 meters?