CaliMag during flowering in coco?

diggs99 said:

What other nutrients are you using for food?

I'm using flora micro and bloom from
GH and I'm using calimagic throughout

Some are using nutes that have lots of CA in it, so not required in that scenario

Regardless, you need the calmag during flower just whether or not you need to add more to your nutes is the question.

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Understanding Cation Exchange in Coco Coir

Coco is known as a neutral grow medium, but there are cation exchange sites in coco. These sites on the surface of the coco fibers will form bonds with particular nutrient cations. The cation exchange capacity of coco is unlike soil or other grow media. There are far fewer exchanges and the exchange sites will become stable (buffered) once they attach to Ca or Mg.

The cation exchange sites in coco naturally come loaded with sodium (Na) and potassium (K) cations. However, the sites have a weak hold on the Na and K cations. In the presence of calcium (Ca) or magnesium (Mg), the sites will release their Na or K cations and lock onto the Ca or Mg. Once the cation exchange sites in coco have locked on to Ca or Mg, they are “buffered” and stay stable.

The cation exchange sites in unbuffered coco can pull nearly all the Ca and Mg out of a nutrient solution. If you try to grow cannabis plants in unbuffered coco, they will experience Ca deficiency. This is tough to correct while plants are growing because Cal Mag supplements have a strong impact on electrical conductivity (EC). As a result, the total dose of CalMag that you can provide is limited, even though it all may be going to the coco and none to the plant.

Buffering the coco in advance is a critical step to creating an ideal growing media. However, even in fully and properly buffered coco, you should continue to provide additional Cal Mag supplement.

Why do you need Cal Mag Supplement If the Coco is Buffered?

The simple answer is that the coco is constantly breaking down. As large fibers of coco break down in the pots they expose new surface areas of the coco fiber. This also exposes new cation exchange sites that will take Ca and Mg from your nutrient solution and reduce the amount available to the plant.

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