the "molecular formulas" are what always throw me off, where ever I read about fertilizers on here or Google, everyone says the molecular formulas lol, I guess I will just have to learn them to make life easier.
It'll become pretty easy once you see it several times. Google is your friend until then
still don't understand 100% what ppm I am aiming for, I presume the calculator has this set to the correct limit, for example KNO3 its telling me how to dose for 7.5ppm, it also lists the measurements of how much to add to a 500ml solution, I presume I just measure them against what the website recommend.
The calculator does report the correct ppm ranges. Be careful to select the daily EI dose from the drop down list for individual dosing. The other is for an entire week. The EI ranges for each are roughly...
NO3 (nitrate) range 5-30ppm
K+ (potassium) range 10-30ppm
PO4 (phosphate) range 1.0-3.0 ppm
Fe (iron) 0.2-0.1ppm
GH (general hardness) range 3 degrees ~ 50ppm or higher
So in this case I would measure 4tsp of Potassium Nitrate and measure to see if it comes to around 30.572g.
If you have a precision scale measuring is more accurate by far. If not the average weight of each is below. These are from that calculator. They can vary quite a bit from nutrient to nutrient but is a close approximation.
Potassium Nitrate (KNO3) 1 teaspoon = 5,200mg
Potassium Phosphate (KH2PO4) 1 teaspoon = 5,800mg
Magnesium Sulfate (MgSO4.7H2O) 1 teaspoon = 5,100mg
The micro mix can vary a gram or more depending on which one they used.
I also have no idea why they would give me epsom salt, is there a way I can test to see if it salt, I don't see why they would give me that lol... are you sure I've been ripped off? if I have I better look at getting the magnesium elsewhere.
You were not ripped off at all. That is a common use for epsom salt. In fact in the calculator the selection is MgSO4.7H2O. Google MgSO4.7H2O and it will show you that's epsom salt. I'm not aware of any easy way to tell if it's epsom salt or not...taste it maybe lol. Don't confuse the term salt with common table salt. Salt
is a chemistry term for ionic compounds. The potassium nitrate is salt peter. Many of the nutrients we use have common names and applications. It is surprising to most the techy sounding nutrients when expressed scientifically are common things.
You may want to read this article
on EI dosing. It will explain a lot in non technical terms for the most part.