does this mean ... ? (EC)

[ruderalis]

hi folks,

I got myself a conductivity meter - aquapro digital water tester AP-2 (HM Digital, Inc.)...
here's a pic:
45944

it gives me measurements in μS ... which for me is a bit confusing :(
how could I compare it to EC?
by EC I mean like:
"
seedlings 0.8-1.0
slightly bigger.. 1.0-1.2
small plant.. 1.2-1.4
pure growth vegging 1.6-2.0
flowering.. 1.6-2.0
"
:)?

it says in the manual that its factory calibrated to 700 μS... has got EC Range 0-9999 (μS/cm)...

i'd be glad if anyone could help me out.. tried digging these forums but i might be a bit "tired" tonight.. so thought to ask to make it perfectly clear :joint:

thanks mates!

[topscouser]

https://www.thctalk.com/cannabis-forum/showthread.php?42772-converting-between-EC-CF-amp-PPM-(-mS-amp-µS-)&p=1068720981#post1068720981

sorted that thread for you mate. hope it helps

[illearth67]

Most feed guides give recommended EC values in millsiemens(ms) so you need to convert your meter readings in microsiemens(us) to millisiemens.
To do this you must divide your readings by 1000.
For example an EC of 800 micro siemens converts to 0.8 millisiemens because 800/1000 = 0.8.
The 700us factory calibration means that the meter was checked against a fluid of 700us (0.7ms) to ensure accuracy before leaving the factory.
EC meters will lose accuracy over time so you will need to check the meter regularly using an EC buffer solution and recalibrate if necessary.
Hope this helps, good luck.

[ruderalis]

thanks topscouser & illearth67 for informative replies :)

I am going to use GHE Flora Series nutes... their application chart (http://www.eurohydro.com/publications/publications/APPLICATION%20CHARTS/GB/CHART-FLORA-SERIES-GB.pdf) states:
"suggested ec : Cutting : 0.4 - 0.6 - Seedlings : 1.2 - 1.8 - Growth, flowering & fruiting : 1.8 - 2.2"

so in this case, the seedlings should have 1.2-1.8 millsiemens (ms), according to my EC meter it should be 1200-1800 micro siemens (μS). and there is no need to know part per million (PPM) reading.

am I correct on this one :) ?

I just got really confused on a chart yesterday.. but didn't realize that it shows conversion between millisiemens & parts per million.. doh, don't need that :P i've got my readings in micro siemens anyway :)

the chart i was talking about:
45976

thanks!

[illearth67]

That's correct mate PPM is an old way of measuring EC and you won't need to worry about it.
All modern feed guides use millisiemens so it's really quite simple just to convert from microsiemens as I described above.
Remember feed guides just provide a ball park EC figure, some plants can handle more nutes and some less so you must learn to tell the difference between a nutrient deficiency or a nutrient burn.
That will come with experience in the meantime use the cannabis infirmary if you run into any problems, good luck for now.

[The Lost Soul]

Great wee chart there lilearth mate.
Very helpful as always.
Cheers

Sent from my iPhone using Tapatalk to save that chart to my phone so I can print it up......boooyaa!!

[ruderalis]

That's correct mate PPM is an old way of measuring EC and you won't need to worry about it.
All modern feed guides use millisiemens so it's really quite simple just to convert from microsiemens as I described above.
Remember feed guides just provide a ball park EC figure, some plants can handle more nutes and some less so you must learn to tell the difference between a nutrient deficiency or a nutrient burn.
That will come with experience in the meantime use the cannabis infirmary if you run into any problems, good luck for now.

thanks for clearing things up :)