Transferring everything may cause a spike, just be sure to have some fresh sw
mixed up before you move everything. Syphon all the water into a rubbermaid tub, (place some in a seperate container for your fish) place your live rock in there, move the sand to the new tank, place your rock then return the water and fish. Once things settle down, then do a water change and check your parameters. If they are high, prepare to make another pwc
. I did this transferring a 110g to a 55g and had no problems. I did do a large (about 40%) water change though just to be sure.