These phrag seedlings that I have had for a year ...have pretty much done NADA , so I am experimenting with them in SH. I do not know what kind of "rock" these are, as they were given to me. I found the cups in the home canning/ freezing section of boxstore. They seemed to be perfect for my situation, very few roots on these guys ! One paph is in it ,too.... .. little or no roots. Does everything look OK ?