If you buy "dead rock", then there is likely stuff on it that will still decay and yes that would cause a mini-cycle. If you buy rock from marcorocks.com or other true "dry rock", it shouldnt cause a mini-cycle. Marcorocks Key Largo rock is terrestrially mined and its from an ancient reef that has since been dug up, kinda like an archaeological dig. Since it hasnt been in water in a LONG time, it has nothing living on it to die off. Just rinse it off with some water and it shouldnt cause a cycle at all. Most people use the dry rock to form the bottom layers of the reef and then add the
LR to the top, not sure what the benefit of this is, just something I read.
Dave
Dave