When to check PPM level

Hey guys,


After some experimentation and some failures I've come to the conclusion that I could be measuring PPM levels completely incorrectly.... My main question being this... should I be checking the PPM levels after the initial veg/bloom nutrient is added and before the others are added (liquid karma, humex, Sweet etc)... The reason being is I am finding extremely hard to keep the PPm levels between 400-500ppm during the early veg stage without severely cutting back on all things I add.. so it's leading me to wonder that I should be adding the food nutrient... checking the PPM level.. getting it right and then adding everything else..

example --

If I use 1/4 strength of everything

Dyngro Veg
Liquid Karma
Sweet
Humex

the total ppm comes out to about 600 with 2.5 gallons of water in my dwc.. However I feel like I could be severely limiting the plant from the Dyna grow supplement due to this..

So should I ...


Add the 2.5 gallons of water, then add the Dyna Grow... take the PPM reading and measure it to about 4-500.. and then add all of the additional additives?

I'm noticing that stuff like sweet is 0-0-0 and liquid karma is .1-.1-.5 however they do raise the overall PPm levels... but they shouldn't be adding any stress the to the plants right? or am I completely wrong here?


Thanks in advance for your responses as I'm truly confused now..

Thanks!:rastasmoke:

That PPM number is based only on your MAIN macro and micro nutes. If you are using the manufacturer's full product line than just follow their recipe regardless of the PPM.

that explains a hell of a lot... thanks a ton... I've been doing it completely backwards..

Starting with known-good tap water, add the food nutrient, take ppm reading, get it right, add the supplements, adjust the pH, and walk away.
Starting with purified water, add calmag up to 250ppm, then the food nutrient to where you wnat it, then the rest, adjusting pH LAST of course.