There is no difference at all... The only difference is when trying to communicate your dosages to others.
That's the first intelligent thing you have said. It's also something I have said in this thread many times.
I'm going to try this again.....remember, the context
is not about how you measure!!!! Measure how you want. The context is how you understand the numbers. Look at post # 2.
https://www.thcfarmer.com/community...d-nutes-side-by-side-test.75869/#post-1524997
The only nutes I have ever used (meaning worked with thoroughly) are
NFTG (700 scale) and GH (500 scale). So Ken, when you say that 1600 ppm = 2240 ppm, I can assure you, you are wrong. (I think I saw you say it). Mathematically, you are wrong too. This is the correct statement 1600 ppm ≠ 2240 ppm. If you think I'm being overly scientific about it, I assure you, it carries over to the real world (as most science does).
A lot of people think EC is somehow "universal" or "superior." This is false. EC is actually meaningless, the number itself. See this chart?
A lot of people see the above and they say, "I use EC because it's (universal, standard, insert word here)." Because EC is on the left and stable and PPM fluctuates. This is incorrect. Common sense, math, in every way, it's wrong. Mathematically, you can have as many rows as you want (horizontals) but you want the least number of columns (verticals). That is how you establish common denominator (universal).
If I put PPM's on the left, and the EC's on the right, ppm will now appear stable, and it will appear that EC fluctuates. There will also be fewer columns because across all the scales some of them will share EC values. E.g. 50 ppm across all the above scales will be .1 EC.
So, if you are saying EC is superior because it's "stable", you are wrong. Mathematically, that's how it
should be arranged (ppm on the left). But whatever, it's really not meaningful, so long as we know the scale differences. Both numbers mean the same thing in the end. Try to follow me here.... Rox provided me with charts to show Lucas ratio's for .5 and .7.
So, look ^^ Lucas Ratio's....estimated PPM is just about 1000 at .5 and estimated EC is 1.91. Great. Now look at what happens if we make it 700
Here is what happens if we dilute it. Still Lucas ratio's.
Same ratio, now .7 is just about the same, 1000 ppm. Look at the estimated EC, 1.43....it's 40% lower. Same PPM, but now the EC is
off. Same ratio's, same ppm, (and the above two pics mimic what would happen across scales) but the EC is 40% off. That's because that is what PPM does. That is it's whole purpose. It is simply so we can take numbers and cross scales with them...and they mean the same thing.
Assume you are on .5 scale, and I'm on .7 scale. If I give you my recipe in EC (I'm at 3.2 on the .5) and you mix it with your .7, you are going to be at 2240 ppm. 40% difference and 2240 is extremely hot. And I can tell you from experience, you are gonna burn the daylights out of your plants. I don't care if they are heavy feeders, unless it's a tree, it won't take that much. The EC value, of 3.2, does not travel across scales. Therefore, it is not universal. Within any scale, EC is fine. But if I give you a nute recipe with EC, and we are not on the same scale, one of us is going to be
extremely hot.
"If I mix my solutions, one .5 and one .7, by EC, and let the buckets dry, they will be the same dry weight. If I mix them by PPM and let them dry, the dry weight is 40% different."
Correct. That is what PPM does, and has been doing the entire time. It takes the EC "fluctuation" out of the equation so you can cross scales. See that 40% difference that keeps popping up everywhere (the 500 and 700 = 40% different)....PPM simply takes that out of the equation, so you can cross scales and still be at the same relative potency. So, when people say EC is "universal", "Standardized", "doesn't change", it's untrue. Maybe this is too far for the argument to be understood, but to say that EC, is universal (which, in every context I've read, they mean they can cross scales with it) is to say that 1600 ppm = 2240 ppm. < That, is demonstrably untrue. PPM, is the closest thing we have to a "universal" figure. If I gave you my lucas recipe in PPM's (I'm on the .5) , and you copied it (and you are on the .7), we would both be much closer to comparable potency. With EC, there will be a 40% difference. That is the entire purpose for PPM....to remove that. So, if you are talking about ending dry weight etc, yes, if you measured by PPM, across the scales, dry weight will be 40% different. That isn't proof that ppm inferior somehow, or inaccurate. To the contrary, that is what it's supposed to do. And it's what it's been doing the entire time.
"We don't even know if the scales are correct."
Yes we do. There is actually no such thing (in real life) as a .5 and a .7 solution. Those numbers were simply chosen to reflect the difference of 40%, which was ascertained by a dry weight assessment. If it was a 60% difference, we would be using .5 and .8, get it? Those numbers are simply to cross scales, but they are not arbitrary. Someone has done the measuring and figured out there is a 40% gap.
"EC is stable, ppm fluctuates"
That's because of how the chart is arranged. I can put PPM in the left column and make it look like EC fluctuates. In truth, neither one "fluctuates." The scales simply have different correction factors (the tables). EC alone, ignores the correction factors, yet some people believe it's "universal." It's only "universality" is that a unit of EC is a unit of EC. The same way a mile is a mile, and an inch is an inch. It does not translate to potency. I checked this with not one, but two chemists. And they verified what I have been trying to explain all along. Just because a chemical has a specific EC value, does not translate to potency. Again, 1600 ppm ≠ 2240 ppm.
"They both mean the same thing"
Within the same scale, yes they do. One is simply a multiple of the other (to make it "universal") An EC in the .5 scale will carry pretty closely anywhere in the world, with other .5 nutes. When it ceases to mean the same thing is like with the
NFTG and GH. You can no longer use EC and expect similar potency. With PPM...you could. With PPM, the scales are no longer a factor. So long as you are using the correct meters....e.g. using a .5 TDS meter in .5 solution, a .7 meter in .7 solution.
"EC is the better figure because that is what we are actually measuring"
The only reason we are measuring EC is because it's such a simple test. But the EC value itself is meaningless. If it was the only thing that mattered, we could just dump a straight water/salt solution to whatever EC we wanted. But, it's what the EC indicates that's important...that's it. You can use it alone, within a scale to judge potency. But also, EC, multiplied by ___ will essentially be the same. In other words, in the same scale, it doesn't matter. PPM is divined from the EC figure. It's a multiple, it is the same. But if you want to cross scales, you must take that extra math step to be in "common denominator" mode, which is PPM.
The way that many people understand the EC/PPM connection, or the how's, why's etc, are actually incorrect. It's isn't "universal" in the way that people think. The only way it could be, is if all nute lines had the same EC to PPM scale....and as we know...they don't.
PPM, is simply taking the EC number an extra math step, to make it "universal." It's not
better than EC. Neither is EC better than PPM. But if you want to talk "universal", ppm is the number you want.
PPM = common denominator. Not EC. Measure how you want...but understand what you are talking about.
The fundamental principle being misapplied here is that an EC is an EC. That is true. But we are using EC to try to determine relative potency. The only way that this works, "universally" (across all scales) is if every single nute line had the same EC to PPM ratio....but they don't. That's why we have the scales. But it seems that many people can't "handle" the math, or are influenced by entrenched thought. But what I explained above, is correct. I had a chemist check it...and they had another chemist check it....
And the concept that EC would carry the same meaning across the different scales, well, I don't know. Find your own chemists and listen to them laugh at it. EC, across scales, will not reflect potency. Ppm will. I don't know what is so hard to understand about that.
