New sandbed but old rock/ cycle?

[Doug]

I,m setting up my regular 50g to play around with a plenum system again. Ran one with some success about 15 yrs. or so ago.

I have over the plenum a couple inches of 5mm crushed coral. Its from another tank, so likely phosphate loaded but thats fine. I rinsed it well before using. The top few inches is 2mm aragonite. New and again, rinsed.

Its currently running about 1/2 full with used tank water. I know the sand will take months to become active but wonder if I move my reef over in a week or so, if the sand cycle would be noticeable.

I have lots of well aged live rock to compensate for it. Would it not be like adding new sand to an established tank? Or moving ones system and adding new sand?

Thanks. Looking for thoughts.