Make sure you keep any biological media from the operating filter, in aquarium water, and set up that QUICK, so the colonies do not die off.
Transport the fish in a bucket with about 3/4 full the present aquarium water. You can save a couple buckets of the original water if you want, to put in your system, but the good bacteria is on the "SURFACES" like the gravel and stuff. Do not allow the gravel, or decor/rocks to dry out, this will help preserve some of the bacterial count. SET IT UP QUICK with treated water (using a dechlorinate, dechloramine agent).
About the sea rocks.....You should be able to use them just fine. Rinse well in regular tap water, let them soak a few days in water, to leach out any biological waste that may have been dried on, rinse again with some de~chlorinated water, and all should be well when you put them into the tank.
