Botanicare CAL-MAG PLUS

[Iammygod]

Hi every1.

it contains:

● 3.2% Calcium derived from Calcium Nitrate, Ca(NO3)2. Calcium Nitrate has N/Ca ration of 28/40.

● 1.2% Magnesium derived from Magnesium Nitrate, Mg(NO3)2. Magnesium Nitrate has N/Mg ration of 28/24.

Applying 3.2% Ca from Calcium Nitrate and 1.2% Mg from Magnesium Nitrate will add 3.2×(28/40) + 1.2(28/24) = 3.64% Nitrate Nitrogen. But this bottle contains 2% total Nitrate Nitrogen. How/why?

 

[DoctorJohnson]

Oh man, that's an interesting little stoichiometry question, but it's too late in the day for me. Just a thought: most manufacturers will answer customer questions at the support page of their website.

 

[Iammygod]

My plan is N/S=6.4 and Ca/Mg<3. So i have to boost both S and Mg without adding more N and Ca to the solution. At 91.15 ppm Nitrogen, Sulphur should be​​​​​​ 14.2 ppm. So i need 9.0 ppm more S. If i get this 9.0 ppm S form MgSO4, it simultaneously adds 6.75 ppm Mg to the solution and Ca/Mg=99.3/(27.64+6.75)=2.89<3

I wanna know, how and why there exists only 2%Nitrogen in BCMP not 3.36%

The other problem i have is Silicon. I have a solution of 28% SiO2, 22%K2O. If i use this to get 30ppm Si which is not much Si in veg, it adds around 42ppm elemental Potassium, 2 thimes more Potassium than what i think is sufficient Si in coco. For Si to be effective it needs to be applied through entire gow. Can i efficiently feed my plant with Si in veg using foliar feeding? How?

 

[DoctorJohnson]

I'm all for the scientific approach, but you might just be overthinkin' it a little. I would be willing to bet that the bigger fertilizer companies have a PhD or two back in the labs, and that their off-the-shelf formulations are all you need. But of course if you enjoy doing the science and tweaking your fertilizer mix to the nth degree, I'm all for that! Please report back if you discover anything interesting.

 

[Iammygod]

Here is the result of
128-20-58-120-50-15~0 (N-P-K-Ca-Mg-S-Si) on Coco/Perlit 2:1

day 24 from seed

 

[Iammygod]

I don't agree. There is nothing special in many bottles.

 

[DoctorJohnson]

> I don't agree. There is nothing special in many bottles.
I didn't say or even imply that "many bottles" have anything "special" in them, just that it could be easier to just skip the math and use an established regimen, but if you like doing and the control that gives you, that's great. You plant looks beautiful, by the way, so you're clearly doing something right!