Nutrients Cation exchange and coco conditioning explained

[GeorgeCloney]

I plan on transplanting some seedlings in the next few days into coco.
Going coco is something new for me ( versus soil in the past with a few grows under the belt).

My question is...
I bought some CANNA coco brick and need to soak etc...

In doing some research on cocoforcannabis.com,....it is advised to double soak the coco in a calmag mix of 7.5 ml per gallon to condition the coco.
Why 7.5ml,...not 2ml or 30ml...
How do we get to these numbers to properly condition the potassium & phosphorus to balance the calcium and avoid a calcium deficiency?

In doing so, will I not create a calcium surplus causing nute lockout to the seedling??

Can someone with experience on the conditioning of coco please give me ( us) ,...a better view of the big picture on conditioning.

Cheers to all,
GC

 

[Mañ'O'Green]

I am sure you are talking about a specific brand of Cal-Mag that the measurement subscribes to. A better number to work with is the PPM in a PHed water solution that would be universal, as different vendors will have different strengths.

We have a whole section on just COCO growing. the explanation for the cation exchange is probably in there; basically the coco acts like a magnet attracting the ions of calcium binding to them and keeping them from being available to the plant. once the magnet is full then the remaining Calcium is available to the plant.

https://www.autoflower.org/forums/discussion-growing-with-coco-coir.244/

 

[GeorgeCloney]

That was an excellent answer ,
Thanks ManoGreen