I have used gypsum in coco coir.Does anyone have experience amending their coir with gypsum? Apparently it adds to aeration as well. Got the idea here: https://www.thcfarmer.com/community/threads/meeks-2013-dapper-grow-log.53463/page-14#post-1100572 (post #263)
@nMEEKS suggested 150g/50l (approx 1.75 cu ft, or a standard bag)
Maybe amending crab meal in the first pot for veg (for the calcium and chitin) and gypsum in the final pot for the end of veg and flower (for the calcium and sulfur).
fyi, Nmeeks is growing with a custom salt mix/ water soluble nutrients.
He is unable to get higher calcium levels in the soil from calcium nitrate without adding more nitrate and calcium.
The thinking is to add gypsum to try and bring up the calcium levels.
Hope that helps