Maybe..just maybe... you are asking the wrong question... ( You PM'd me so I will answer you directly tomorrow after work).
I just took these pic today (for somone else) of my single plant that is 36"by 28" that I gave almost no nutes to. Mostly just my home made tea (which has nutes in the end) and water. Nothing too harsh... in fact I over did it a lot. I need to cut back a bunch...but since it was all natural not chemical it all worked out.
And I stunted it mid bloom so it should be much bigger.
Maybe the trics come through?
and the lower ones are starting to show some awesome purplish coloring. (hard to see under the HPS)
But I absolutely did not need to max the nutes to do that.
The things that we need to know is what soil are you using and what does it contain. if you were using a supersoil then most of your nutes will be there and may need to use next to none.
Or maybe your soil is poor then you need to add more. more details on what you are growing in will help.
Dont add nutes at first though. just watch plant, if it goes real light green then it means the plant is hungry so then start adding nutes 1.0ec is a good start on a small plant and upto 1.4ec.
if plant is real dark green just add water and if tips are burning the soil is too strong.
Add beneficial bacteria to keep soil live, that will help alot.
k guys i aint no rookie i know how to read what the plant need and that's why I'm askin how should i respond to 500ppms runoff promix bx 7 weeks old from seed ...just flipped 12/12 they r so happy no nute burn ...question is should i feed more then 500 ppms or under 500ppms ..old man that taught me...always said chem is like a steroid to the plant ... to maximize the plant potential u have to find where they r happy wid the ppms ...my tap water is 7.1 ph 150 ppms..i will include that 150 to my reading because there are nuts in tap water.. after one week i would start at 200 2 week 250 3 week 300 4 week 350 5 week 400 6 week 450 7week ...runoff is 450-500 every plant a little diff...i feed feed water all phd ...when i notic there livin a little to rich i feed water feed water..what u guys think ...i use airstones and fish tank heater and 48 hour water
those ladys look very happy what i have learned some strains like a lot of nute some like little some don't even need any as long as theres some organic matter in the soil
Yeah I think you knew I was being sarcastic right... LOL But since you aren't on and I PM'd you back I will just dump some of the info here.
You are correct about them Chems. You hit the nail on the head. The reason why organic works better is it self regulates and has a more balanced uptake. With straight chems you are in charge of nailing that ratio and there is little choice. You get the ratio on the bottle unless you mix to different bottles. Many brands have multiple bottles just for that reason. I like to cheat and go organic...but in the end it is all chems. Beneficial microbes really make this all much smoother.
And absolutely different strains have different req...another reason using one set of bottles the same way every time doesn't really get you there. All good growers listen to the plants.
As to your question...the reason I was saying that isn't the right question is it is fundamentally based on a misunderstanding of how nutes are used in the plant. And I was being sarcastic because we post this on here nearly daily.
The "good" range of nutes is actually very wide, and similar to pH, as long as you are inside the good window then you are good to go.
Being on one edge or the other can be bad. Being on the low side isn't that big a deal you can easily recover that if an issue comes that pushes you a bit low. But being on the high side can be real bad if something pushes you over the top. Even worse lets say your pH drifts up and you start to think you have deficiencies and are actually nearly over concentrated already. Then you up the nutes and are putting in toxic levels but don't realize it until you realize you have a pH issue. Then you fix it but don't flush and bam you are killing her.
Another thing that can happen by running to high requires first an explanation of how it supports photosynthesis. The nutes are only needed in small amount (relatively) and are only needed to support the results of photosynthesis. So if the photosynthesis goes down (lets say you did some serious pruning) then the plant starts sucking up way more nutes then it can use and you start to burn it fast. There are a umber of things that we do that may cause the photosynthesis to quickly drop off. It could be the humidity or temps go bad on us and the plant is stunting. But in any case if we are riding high and photosynthesis drops... unless transpiration drops with it... we will start burning plants.
But the real gem is part of the function of the leaves and Mycos is storing up nutes for use when they are needed. So we can ride in the middle or even a bit low and then if things happen we didn't catch or we want to go do some crazy pruning and training then we wont burn the plant.
It is just a good insurance policy to be more in the middle of the window than on either edge.