MS levels ?

[Gruff]

G'day guys, just a question about nutrient levels. First time growing in doors, used to just put seeds in with the vegies and just water in but growing now medically for personal use. I bought an EC metre and was told on setting mS that it should be reading 1.9 , just wondering what all this means ?
Cheer's Gruff.

 

[Stunned]

what the hell is mS?

 

[Gruff]

Its a HM Digital TDS/EC Meter com-80 and it has 4 settings, the first is 'mS', what looks like a backwoods 'yS', ppm 0.5 and ppm 0.7 . Have a look at the link below.
HM Water Quality Tester EC/TDS Meter COM-80 - Pakenham Hydroponics

 

[Scientific]

what the hell is mS?

millisiemens, a measurement of conductance. When you see people quote EC numbers that aren't in PPM (like 1.9), they are giving them in mS/cm.

To convert mS to PPM, you multiply by 1000 and then divide by 2, so 1.9 mS is 950 PPM.

So anyway, to get to the practical part, you stick the meter in the liquid and it sends an electric current between the two pins. The more fertilizer salts there are in the solution, the more current flows and the higher the number.

An EC of 1.9 (950 parts per million) is pretty concentrated.
I give the dwarf plants I grow just 400 PPM (.8 mS, usually stated as "an EC of 0.8").
Seedlings get half that.
Big plants that are rocking can take over 1000 PPM (EC of 2).

Make sense? The units are all very techno, but the concept is pretty simple. Unfortunately, to make things more complicated, there are different scales and conversion factors, but the ones I gave you are the ones we use in the pot biz.

(Use the PPM 500/TDS column for PPM)

<edit> I looked at the website. You have a nice meter! </edit>

 

[Gruff]

Cheer's Scientific, that's the answer l was looking for.