First and formost do not move a tank with the sand in it. The bottom is not mean to hold weight. An unsupported tank is a very weak item. You'd be surprised how much weight there really is to a tank with 4" of water. The absolute last thing you want to have go wrong at this point is to see the bottom of your tank give out and see it on the floor. Trust me I've read about it a few times. You'd then be stuck looking for a replacement during the move.
I usually suggest and have had great luck with.
The first thing you should do is mix up a fresh batch of tank water the night before at the new house. It will be the same temp as the house is when you get there. You should do enough to refill the entire tank.
1, Break down the equipment as far as possible.
2, remove any corals and anemones that are loose. Place in individual bags if possible. Place bags in a cooler. If not possible place in small tubs and cover with water.
3, Wear Nitrile gloves. Remove the rock work. Any pieces that have coral or anemones on it should be placed in a small tote that will prevent it from rolling around. It is not necessary to keep the rock wet. It will stay moist. I'd recommend for simplicity, just move it to a rubbermaid tub with a tad of water and cover it with newspapers. The wet paper will keep the bacteria alive. Snails, hermits, stars and such can live or hours out of water. Don't be scared
4, siphon out about 75% of the water. Do not save it. It is pointless. The only thing old tank water has in it are wastes. The important stuff is in the filter and the rock work. These be truth as Anthony Calfo stated at MACNA that he does weekly 95% water changes.
5, Catch the fish in the tank. It will be easier now that the water is low and all the decorations are removed. Bag each fish individually if possible. I also recommend double bagging. Place bags in cooler and shut lid. I recommend having someone take the fish to the new house at this point. They will be under a lot of stress at this point. My reason fo rtaking them to the new place is so that they can begin acclimating to the new temp. No need for them to sit around at the old place for another hour or two and then pick them up and subject them to a ride to the new place and new temp. Best to do this while they are still vigorous.
6, Finish emptying tank of water.
7, with a child's beach shovel or with a dust pan remove he sand and store it in 5 g buckets.
8, tear down tank and stand.
9, move everything to the new house.
the set up.
1, Set up tank and stand including plumbing.
2, Rinse out sand with tap water. This will remove wastes and help neutralize toxins. Your other choice is to use all new sand. New sand is sterile. Might as well sterilize your already bought and paid for sand. I fill up a 5g bucket about halfway with sand. I then add a clean garden hose to the bucket and carefully rinse it. I lift the sand out with my hands throuh the water and place into another bucket. Then transport to the tank. I get a lot of grief over this advice. I've used it several times and have not had any troubles doing so. A huge portion of your bacteria will live through the rinsing and the sand will quickly reseed from the rock.
3, Add as much of the live rock as possible from the coral free box.
4, begin slowly filling the tank from the premixed water. Slow filling will reduce cloudiness.
5, when full I begin acclimating the corals and fish to the new tank water. I do this very slowly as this is a huge change.
6, add fish and corals. I still do this even when the water is cloudy from substrate. It was once pointed out to me that the reefs get this way in storms.
Set everything back up and see how it goes.