# Blue lab Truncheon



## nayr88 (5 Feb 2017)

Hello all,

I have come into possession of one of these and was hoping someone could shed some light of its worth using.
If it is then how The types of readings I am looking for.

A quick play with it I have found

My planted hi tech

Daily dosed and after light out
CF = 10
PPMx700 = 700
PPMx500 = 500
EC = 1.0

My planted low tech (green terror)

CF = 8/10
PPMx700 = 560/700
PPMx500 = 400/500
EC = 0.8/1.0

A glass full of EI TNC Complete

Wasn't clear :/
Would only give me a reading as I pulled the truncheon out. The reading would start at around double that of  my planted tank 

Tap water

CF = 6
PPMx700 = 420
PPMx500 = 300
EC = 6.0

What are these readings telling me and what can I take from this?


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## nayr88 (6 Feb 2017)

Any insight on this would be really appreciated.


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## dw1305 (6 Feb 2017)

Hi all, 





nayr88 said:


> Any insight on this would be really appreciated.


There is page with the conversion factors on it, <"Bluelab Conductivity">.

The "500" and "700" readings are the two alternative values for estimating ppm TDS from a conductivity reading.

The "500" is the conversion factor for NaCl (1ppm TDS = 2 microS conductivity), and I assume "700" is <"an adjustment"> to the "640" value you usually use for mixed salts. _Edit *I've just looked and it looks like the USA uses 0.7 and Europe 0.64._

The CF value is a conductivity factor (index) where 100 microS (0.1 miliS) =  1 CF unit.

The EC value is the reading in milliS.

So "EC"=1 is equivalent to 1 milliS (1000 microS) or 10 on the "CF" scale or 700 ppm TDS on the "PPMx700" scale or 500 ppm TDS on the "PPMx500" scale.

Your tap water is about 600 microS, probably meaning that it is hard, our tap supply is from a deep limestone aquifer, and doesn't have much in it other than CaCO3, and is about 650 microS.

cheers Darrel


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## nayr88 (6 Feb 2017)

You've blown my mind Darrel haha. 
I'll do some reading in that link and come back to decider this.


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