If you do a search here using the word "move" or :"moving" there are tons of threads. But, it's really easy to do just lots of work to get ready for the move. Planning is the key to everything as the move should be made as quickly as possible. If you plan it out, it shouldn't take more than an hour or two. The main trick is to not let the rock be out of the water for any length of time so the bio filter stays intact.
First, you need more saltwater. So, you make up in a large container (new 50 gallon trash can for instance) of new saltwater and adjust it to as close to your existing water params as you can. Make enough to make up the difference between your current volume and the new tank plus some more for "oops" incidents. Another way to do this is to fill the new tank with RO water after you've rinsed the tank. Use the RO water to check for leaks, then make up the saltwater in it and drain it into a new trash can. Either way, have the new water close to the new tank.
If you are planning on moving the sandbed, get some 5 gallon buckets to store the sand in while you transfer things, and if you plan on adding sand get that rinsed and ready too. Don't fill them more than 1/2 way up so as not to crush any worms, etc that you take out with the sand. Personally, I never use the entire old sandbed in a new tank, I prefer to put a new one in and seed it from the old sandbed using like 1 part old sand to 5 parts new. That way, I can put the new bed in days before the move and it's less of a hassle. All you have to do is rinse the new sand, put it in the new tank and cover it with water to keep it wet until the move.
You can use a couple of new cheap rubbermaid totes to store your current rock and livestock-just DO NOT try and pickup the totes once they are full as the handles aren't made for that kind of weight so plan to transfer the rock in other 5 gallon buckets a few pieces at a timeunless of course the new tank is next to the old one LOL. I also like to use new rinsed out small food containers for snails, shrimp or as isolation for delicate corals.
On moving day you drain most of the water into the containers, put the rock and critters in them-remember fish jump when startled so a dedicated 5 gallon bucket with a loose lid is a good idea for them. Also, don't let the corals touch each other-I lost a nice piece by letting it rest against another coral that burned it while I was changing tanks.
Pull the sandbed when the old tank is drained, I use the lunch size square food containers as a scoop. Put it into the new tank, and if you are adding new sand carefully mix it in. Add some of the new water to the tank, and begin to transfer the old rock adding old tank water as you go along. Corals and fish go in last. I usually fill up the new tank with rock and water, and put the fish and corals in a few hours later once the sand has settled a bit. It won't hurt them to stay in the containers for a few hours, provided that you give them enough water or use an airpump and airstone to give them some O2.
Good luck
