It is not recommended to add dry organic amendments that require time to break down and become available to plants in coco alone. The microbial life required to make organic amendments available will also break down the coconut fiber, limiting the coco’s ability to hold minerals by the time the organic amendments have mineralized. Coco breaks down way too fast to use it like a soil mix.This is where the worm poop comes into play.A proper organic soil mix provides the structure to hold and house microbes that coco alone can not. Coco has mainly a negative surface charge that holds primarily positive mineral cations like calcium, magnesium and most of the trace elements. Microbes and organic acids are the main storage units for anions that coco can't hold like the macro elements nitrate, phosphate, sulfate, etc. found in a soil with good structure needed to support life. Worm poop is the work around.