EC meters, new to hydro

I just set up my first hydro setup there last nyt. im not to sure how to read my ec meter correct can anybody give me a little guidence. the manuel that came with it was very vague! Its a 138(II) conductivity tester and it measures up to 0-1999us/cm.

I am using "Marijuana indoor growing" by Philippe Adams, as a refrence but its telling me i need a EC reading of 0.8 for seedling?
with the meter i have the tap water reads 320, when i added nutes it read about 520. i went up a few hours later and it was at 710. what does this mean? i added more water to bring this reading down 540 again but i dont no what it means.

Im using a 8 pot wilma system but only have 4 plants in it.
the nute that i used was canna start, i put about 50ml into 70ltrs of water which is well below what it recommends. I dont what to fry them but i do want to give them all they can take.

I tested rain water around the farm its ranging from 050-094 would this be better to use instead of the tap water?

finally im from N.Ireland if that make any difference
please help asap

Im guessing the reading you are getting is a measurement of ppm (parts per million) of the 'total dissolved solids' in the water.

Do some reading up on this.

Start with wiki -
[h=1]TDS meter[/h] From Wikipedia, the free encyclopedia
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A TDS Meter indicates the Total Dissolved Solids (TDS) of a solution, i.e. the concentration of dissolved solids in it. Since dissolved ionized solids such as salts and minerals increase the conductivity of a solution, a TDS meter measures the conductivity of the solution and estimates the TDS from that.
Dissolved organic solids such as sugar and microscopic solid particles such as colloids, do not significantly affect the conductivity of a solution so a TDS meter does not include them in its reading.
[h=2]Units of TDS[/h] A TDS meter typically displays the TDS in parts per million (ppm). For example, a TDS reading of 1 ppm would indicate there is 1 milligram of dissolved solids in each kilogram of water.

http://en.wikipedia.org/wiki/TDS_meter

Different brands of Truncheons have different EC to PPM conversions. The best thing for you to do would be to find the manufactures website of your meter and see what conversion chart they have.

Moebius said:

Different brands of Truncheons have different EC to PPM conversions. The best thing for you to do would be to find the manufactures website of your meter and see what conversion chart they have.

Click to expand...

cant get find the brand website. It was bought of amaon.

that table makes some sence. im really need to find something like that for my metor. makes you wonder why the manufacturer doesnt put it in the box

green gurilla said:

that table makes some sence. im really need to find something like that for my metor. makes you wonder why the manufacturer doesnt put it in the box

Click to expand...

Does the button on the pen/meter allow you to change from ppm to EC readings? if so then ....

look at which manufacturer in the chart best represents your pen and work off that.

the other option is not to use a pen at all and just dose using ml measures.

do i have to take in to consideration the ec before i add nutes?

green gurilla said:

do i have to take in to consideration the ec before i add nutes?

Click to expand...

Nope ... EC/PPM/CF are all a measurement of the same thing. IMO get a couple of grows under your belt before worrying about this.

btw ... If you start a thread with pictures you'll attract some good advice throughout your grow.

If your meter's range is 0-1999 I believe it's reading ppm's as moebius said, as you can see from the chart the highest ec reading is 3.2, therefore you're reading ppm's.