HELP! What ec scale do nutrient manufacturers use?

[BlueBudz]

i can’t seem to find what scale they are measuring the ppm on. Seems like you could really mess things up if you refer to a different scale then they refer to but how do you know? If anyone has some insight please let me know.

 

[RosettaStoned]

This might give some insight if you haven't read it already...
https://www.thegoodearthorganics.com/tips/ppm/

 

[BlueBudz]

Thanks for that, unfortunately my nutrients are not on that list. (Dutch Nutrient Formula) I’m starting to wonder if I should change. But I bought the big jugs to save money in the future😣

 

[DoctorJohnson]

To convert PPM to the EC measurement shown, just multiply by two: 1000 PPM = 2000 uS/cm.

They are giving the measurements in both PPM and microsiemens per centimeter (which is rare--millisiemens per centimeter, which gives numbers 1000 times lower, is much more common).

The measurements given are just two different ways of stating the same thing, which is how much electricity is flowing through the salty fertilizer mix between the two pins of your meter.

I've gotta say those numbers look high--like too concentrated. I would suggest definitely going with the rule of starting at half the recommended strength.

 

[BlueBudz]

Thanks DoctorJohnson but I’m still confused at the scale their using. Is it EC x500 or EC x700. I have a Bluelab Guardian meter it measures both just need to know what scale to set to obtain accurate readings to compare with my feeding guide.

 

[DoctorJohnson]

The PPM scale you almost always see is based on dissolved table salt, which is EC x500.

The article Rosetta Stoned linked to explains the different scales (which can be confusing--I wish someone would decide on just one and stick with it.)

Here's a conversion chart from Blue Lab: https://www.bluelab.com/knowledge-base-files/Conductivity-Conversion-Chart Note that just to keep things confusing, the chart uses milliSiemens to measure EC, not microSiemens, so the EC numbers in the chart are 1/1000th of what's on your package.

 

[RosettaStoned]

If you use the 500 it's 1000 ppm if you use the 700 it's 1400 ppm both reading 2000 EC. They give you both scales

 

[BlueBudz]

Thank you both, I thought they were suggesting a range of 1000-1400ppm. I do understand how it works just strange that they don’t specify the scale of units.

 

[9fingerleafs]

i made a post exactly about that.. let me look for it

 

[9fingerleafs]

here it is, scroll down to find the charts for both nutrients and meters https://forum.growweedeasy.com/forum/growing-community/68078-very-important-to-everyone-ec-ppm