so i'm sort of going through something similar right now.
we're moving, and as such i'm moving in to a larger tank. i started the new tank almost a week ago with dead rock and new dry sand. i added several sponges from my current tank's sump, a couple small pieces of live rock, and a couple scoops of sand to help seed the biofilter.
i also dosed a bunch of probiotics, and used pure ammonia to bring the ammonia up.
the first day seemed to go well. i dumped a bottle of doctor tim's and a bottle of this smart cycle stuff i got from the LFS. dosed the ammonia, and brought it up to ~2ppm as per the instructions on the bottle. added my sponges from the current system, and waited.
the next day no ammonia detectable, no nitrite, no nitrate either (which was weird). so i dosed back up to around ~1ppm and added some pellet food, a couple pinches, to help give some more nutrients to the system.
ammonia was at 2ppm about 12 hours later, and never really fell. so two days of no movement, i added a couple scoops of sand, a small piece of live rock, and the remainder of a bottle of SeaChem Stability.
two days later, not much movement on the ammonia, i haven't dosed any more ammonia or food since. so i added another sponge, and a small bottle of dr tims.
two days, and the ammonia seems to be going in the right right direction. down to around ~1ppm the last 24 hours, and nitrites finally starting to register.
the only other additions have been daily doses of my home brew phyto. a couple of ounces each morning.
i feel like i could hurry this along if i started moving over a considerable amount of live rock from the existing tanks, but i am reticent to do that for fear of killing off a lot of my pods and other zooplankton during the ensuing cycle.
now the converse example to this is when i moved my 20 long QT system two weeks ago. it's bare bottom, but covered in detritus for various reasons. i did that in one fell swoop, kept the small amount of rock in there wet, but used all new water. i got an ammonia spike with that, but only to about 0.1ppm, and within 18 hours it was gone.
tldr; if you move most of your rock at once, i would except a small cycle. monitor it closely and it shouldn't last any length of time. you have the benefit of being collocated to the new tank as well. however, do things piecemeal, and it could stretch out the length of the cycle.
also, don't believe the hype about bottled bacteria.
