Need help with Bluelabs truncheon

[jumpincactus]

Hey farmers. Happy Saturday!!!

I recently was given a Bluelabs nutrient temperature compensating nutrient meter. No instructions for use.
My confusion is this, I have always used a standard TDS meter and gauged my nutes on PPM.

This truncheon has 2 different ways to measure. Showing CF and EC
One side shows ppm stating ec x 700
On the other side its gauges by ec x 500.

Which one is for an American that doesn't do metric, and is the correct side to use when mixing nutes for hydro. EC x 700 or EC x 500 ??? Your assistance is appreciated.

I sent Bluelabs an inquiry but haven't heard back yet.

 

[blazer]

I use the x700 but some meters read ppm in x500 so I guess that's why a lot people us EC it's kinda the center point for the rest, That what nice about blue lab you can read in all the diff scales!

 

[blazer]

Might see what scale your Old Tds meter was prob x500 then you can use that same scale with the bluelab

 

[leadsled]

Lucas tried to get everyone on the same page by using EC. EC is read the same on all meters.

That way we can share EC and then compare numbers without the messed up math if we are not using the same scale of ppm.

.5 or .7. scale.

Example: If one grower is using .5 scale and another farmer is using .7 scale than the numbers we compare are going to be off.
If I look at the numbers as a baseline for my grow. Does not matter what scale I use.

When it matter is If I compare to another grower I state I am using .5 scale. If I state my strength in ppm. The default setting on a bluelab meter.

Hope that helps.

 

[jumpincactus]

Thanks for the input. I must admit I am still blurry on it all.Why in the hell don't we have a standardized form of measure. When mixing nutes with my tds meter it was simple . I ignored the ec ratios on the bottles and went with ppm's.

This meter is badazz yet why the 2 different forms of measurements is beyond me.

For example if I opt to use the x 500 side a given solution would read on ec at 0.2 with a ppm of 100

Then on the x 700 side with the same solution it would show 140 ppm and a CF of 2 I'm assuming CF= conductivity factor.

So if I'm mixing bloom nutes and shooting for say 1200 ppm thats shows an ec of 2.4 Then rotate to the other scale and for the same mix it shows a ppm of 1680 and cf of 24

Am I over thinking this?? I want to KISS it and I'm not sure why there are 2 ways to go about it. x 500 or x 700.

Is the 500 or 700 the conversion factor for metric or imperial measure??? And which is which? 700 for metric and 500 for imperial? Would be easier too if I hadn't just done a dab of shatter I suppose.:confused:

 

[jumpincactus]

Thanks for the input. I must admit I am still blurry on it all.Why in the hell don't we have a standardized form of measure. When mixing nutes with my tds meter it was simple . I ignored the ec ratios on the bottles and went with ppm's.

This meter is badazz yet why the 2 different forms of measurements is beyond me.

For example if I opt to use the x 500 side a given solution would read on ec at 0.2 with a ppm of 100

Then on the x 700 side with the same solution it would show 140 ppm and a CF of 2 I'm assuming CF= conductivity factor.

So if I'm mixing bloom nutes and shooting for say 1200 ppm thats shows an ec of 2.4 Then rotate to the other scale and for the same mix it shows a ppm of 1680 and cf of 24

Am I over thinking this?? I want to KISS it and I'm not sure why there are 2 ways to go about it. x 500 or x 700.

Is the 500 or 700 the conversion factor for metric or imperial measure??? And which is which? 700 for metric and 500 for imperial? Would be easier too if I hadn't just done a dab of shatter I suppose.:confused:

Well I got a response email from Bluelab, here is their narrative.

CF & EC are measures of electrically charged nutrient ions in a solution. Pure water doesn't conduct electricity.
Water only conducts electricity due to impurities in the solution, in our case the electrically charged nutrient ions.

PPM measures parts per million. There are many different scales used for industries around the world and for a many different reasons. Did you know there are more than 2 scales? The most widely used in hydroponics is the 500 scale 650 scale (in the US) and other parts of the world the 700 scale.

Whats the difference?
The ppm 500 scale is based on measuring the KCI or potassium chloride content of the solution.
The ppm 777 is based on measuring the NaCI or sodium chloride content of the solution.
Individual nutrient ions have different electrical effects.
The true ppm of a solution can only be determined by a chemical analysis. ppm cannot be accurately measured by a CF or EC meter. They are present on Bluelab meters for a conversion guide only. The conversion is as follows,

2.4 EC x 500 = 1200 ppm(500 scale) or 1200 ppm /500 = 2.4 EC
2.4 EC x 700 = 1680 ppm (700 scale) or 1680 ppm /700 = 2.4 EC

If you are reading from a book or a bottle of nutes that says you need to grow your crop at 1680 ppm how do you know what scale the writer is referring to? Is the scale on your meter right for the job?
If the book was written in the USA, it could be 500 or 650 scale. If the book was written in the UK it could be the 700 scale. And if it is in Australian could be any of the 3 scales or a couple of more.

If you must grow using ppm you need to know the following
1. What ppm scale is the written instructions/book referring to?
2. What ppm scale is you meter using?
3. What calibration standard should you use for your meter?
4. What ppm scale is your nutrient supplier using?

Well after all that I'm either dumber than a box of buds or I just don't get it.

I think I will go with the 500 ppm scale and call it a day.

 

[blazer]

Ok maybe this will make it easier Tds x500 PPmx700