What do you use and why EC, TDS, PPM

I've been using TDS just because my hydro store recommend it. What's the difference between the three and what are the pros and cons of each?

it is a f#@king conspiracy

It is all the same thing sort of...... this is from the Blue Lab website


EC stands for Electrical Conductivity. Nutrient ions have an electrical charge. EC is a measurement of all those ions that have an electrical charge. The more electrically charged ions in a solution the higher the EC reading.
CF stands for Conductivity Factor. This is exactly the same as Electrical Conductivity (EC), but does not have a decimal point in the reading.
ppm is parts per million. This is not a measure of electrical conductivity in a nutrient solution, therefore cannot be accurately measured by an EC meter. They are present on the Bluelab Truncheon as a conversion guide only and the scales of ppm they represent are noted. To convert from EC to ppm, simply multiply EC by the ppm scale required, e.g. 2.5EC x 500scale ppm = 1250ppm. The two scales Bluelab use are; 700ppm and 500ppm scale. There are many ppm scales around, but these two are most common.
TDS is Total Dissolved Solids. This is the 500ppm scale.


It is different ways to express the same thing

if you want me to try and explain it, tds is the "root" and parts per million is EC x (500 or 700)=PPM
You can set your PPM meter to go into 500 or 700 mode
but if you really think about it a PPM meter is only needed if you want to get down into hundredths in EC
cause your EC meter reads out in 0.0 where ppm would give you the 0.00 making things a little more on the ball
but hey if you dont really think you need it like above said, its a scam

Bluelab truncheon

has em all simple,easy,dependable.

First off its not a conspiracy.
There is just different modes of transportation to reach a destination.
Just like you can drive a car, truck, or motorcycle to get work.
Some people really need to have a meter(hydro and such).
I personally don't worry about any of that to much as I am organic.
I don't use my meter much but I would never sell it. When I do need it, I REALLY need it.
I work with ppm cause it is more precise.
GL

Friedrice said:

First off its not a conspiracy.
GL

Click to expand...

That is what they all say,Friedrice is in on it

Nizza said:

if you want me to try and explain it, tds is the "root" and parts per million is EC x (500 or 700)=PPM
You can set your PPM meter to go into 500 or 700 mode
but if you really think about it a PPM meter is only needed if you want to get down into hundredths in EC
cause your EC meter reads out in 0.0 where ppm would give you the 0.00 making things a little more on the ball
but hey if you dont really think you need it like above said, its a scam

Click to expand...

Sorry, that doesn't sound right to me. How could a measurement become more accurate by changing units?
Why would they keep buliding bigger more accurate scientific equipment if they all they needed to do to become more accurate is multiply/divide by numbers?

Example:
Suppose I measure the length of my dick to be 11.1 cm. I can restate this as being 0.111 m, has the measurement gotten more accurate? No, even though I measure to the thousands place instead of the tenths place, its the same precision (the same number of significant figures).

In fact, PPM is less accurate. The conversion factor from EC to PPM can only be calculated exactly in theory. This is because different elements contribute differently to EC. For example, take a million molecules of distilled water. Add one NaCl molecule. Measure EC. Now take another million molecules of distilled water. Add one KCl moleules. Measure EC. You will get a different number, even though both solutions have 1 PPM of disolved solids. So you would have to add up all the contributions to EC for each atom of each species in the nutrient solution to come up with this number. In real life, this is a total waste of time, and more information than we need. People just use a number (usually .5k or .7k). This number is not calculated as accurately as the measurement of EC, so multiplying by it actually makes the measurement of PPM less accurate than EC.

So EC is the most accurate measurement. That being said, PPM is the accepted standard that is used, since its the number we really care about. I choose to convert to PPM using the .5k number [PPM = (EC)*(500)], because I like to be conservative with my nutes.

I use EC simply because it was the first way I was told about it AND the first pen I bought measured EC
(essentials EC pen, pH pen, pH 7.0 and EC 2.8 Calibration fluids, pH up and pH down).

I have learned the equations to turn EC to CF, CF to PPM an PPM to EC....
EC x 10 = CF
CF x 50 = PPM
PPM / 500 = EC
They all measure TDS
just with different scales.

I use EC bc its universal where as you see above, diff meters use different rates.

My ph meter is bluelab and my ec meter is HM. It doesnt matter which you use until people start telling you to run a specific PPM or youre trying to follow a feed chart unnecessarily to a T.