If you haven't done it already, I'll tell you how I went from 29 to 55.
First, I put new sand into the 55 and filler partly with old tank water. I then transfered the rocks over but didn't really position then. I moved the 29 out of the way and slid the 55 into position, positioned the rocks, filled the rest of the way with freshly mixed water, and then siphoned out the top 1/4" or so of the old sand bad and spread it around the new tank to help seed the new sand. Caught all the fish and put them in. Cleaned up the mess. Took me a couple hours.
Someone stop me! Please! But... not just yet...
55 Gal Tropical FW
55 Gal Mixed Reef