How long will it take to transfer fish from my old tank to my new tank?

I recently brought a brand new 180 gal aquarium. My question is how long will it take for me to be able to add my fish from the old tank to the new tank if I used almost half the water, majority of the sand and all the live rocks from my old tank of 125 gallons. Its been up and running for about a week. I tested the water today and my PH is around 8.2-8.4, nitrate,ammonia, and nitrite are all like 0. Is it safe to convert all twelve of my fish to the new tank?