I still don't see where the Phosphorus is coming from unless it's trace amounts in the eggshells. Haven't studied chemistry in 30-odd years, but elements don't just appear out of nowhere, right? So if we are combining calcium, carbon, and oxygen with more carbon and more oxygen, the P is coming from... where exactly?
"There is some phosphorus in egg shells, although they are about 95% calcium carbonate. I should probably amend this recipe since egg shells are much lower in phosphorus than other common sources you’d use, bones for example."
Any protein based from an animal, when DECOMPOSING can attract / give rise to various pathogens.
dank.Frank