Generally you'll want to change your
nutrient solution every week or two. I'm not familiar with the nutrient your using, so can you post a link to the calculator?
But I did do a search for the product to see what it was and one website states this about it:
"Coco coir requires an extremely precise composition of the various minerals, a task that you can safely leave to Cocos A & B."
This is simply a bogus claim, coco coir dosen't require a different nutrient solution than other hydroponic growing medias.