I have a totally different take on this cycle based on pics that show purple rock
You take two completely different actions regarding ammonia depending if that coralline is real or if it's painted on/simulated rock kind
Ask the seller
True purple coralline means already cycled rock. You can't have true coralline rock that is missing any needed bac
Insert scenario "what if someone medicated it and didn't tell"
Doesn't happen
It's either aquarium cured (cycled elsewhere transported to you, cycled) or its fake painted rock that you must cycle
Solely off the coralline we need no test info so far
If that was live rock you moved from some other tank into your house, you could add a coral frag and get going lightly. If it's painted, then you take opposite action and add ammonia, wait, and add some bottle bac too
That much coralline right off the bat too good to be true. I bet that's a product called real reef rock which is painted coralline and in most cases, precycled see their website.