Hi Darrin,
I just went through the "rock swap" these past few weeks. Here's what I did - what I consider to be optimal. Hopefully these notes can help you and others.
I took out all the old live rock but left the sandbed. I took out all my corals and fish and put them in a rubbermaid.
I put all of the new raw uncured rock into my tank on top of a trash can lid. I ran the lights and skimmer HARD to speed up the cycle as quickly as possible and I also put a few pieces of the old live rock in my sump to help out. The lights help a lot as they spur algae growth and as you know, algae locks up nutrients very well.
By the end of a week I was down to zero ammonia so I put in some Turbo snails. They did a great job eating up the algae and wiping down the rocks.
This weekend, I took out EVERYTHING and put in a new sandbed. I kept the top about 1 inch of the old sandbed as that's where all of the critters are. After arranging the rock and sand, I spread this "seed sand" on top of the new stuff.
So now I basically have a whole new tank. As soon as everything settles down, I'll put my fish and corals back in.
Cheers
James
