how do i know when safe to move to new tank?

Hi guys, i have a 16 gallon reef tank with corals and fish in it. I just bought a 40gal tank. I put new live sand in it a week ago and tons of new live rock and new saltwater. I has been running for about a week like that. I also put 2 scoops of sand from the old 16g tank in it. The 16g is still running. Do i have to cycle the new tank? (if so, what is the best way to do this?) How do i know when it is safe to move the corals and fish to the new tank? I heard that you have to make the ammonia "spike" first. Is that true? How do i do that?



Any suggestions much appreciated!!