Instant Cycle - Switching tanks?

[Coasting]

I DO NOT have the room to have 2 tanks running at once until I sell my cichlid tank which wont happen any time soon.

I can no longer keep the "giant swimming pool" in the middle of the basement. I then added a large bin with rocks beside the "giant swimming pool" which is beyond in the way of any space we did have left to walk in that room.

This new tank will be going in exactly the same spot as the old tank, I can move the old tank temporarily beside the new tank but that will displace where the couch and side tables currently are (moving them to the middle of the living room), any longer then a week out of place and I think I will be kicked out of here.

My sand bed is Dirty Dirty Dirty! I know if I disturb it, it will let up all sorts of nastys and I would rather not kill everything.

If I wasn't using new rock, I dont think I would care about any of this. But I know regardless of how "cured" the rock you buy is, theres going to be die off which will create a cycle. That is what my concern is.