How long ago did you set the tank up and add the live rock and sand?
I set up 2 tanks in the past year doing what you did, using live rock and sand from another reefer's tank. For both I also added biospira to boost the bacteria. The 75 gallon had a full complement of fish and corals within a month and never had a problem, nitrate, nitrite or aminia spike.
The 125 gallon was a different story. I added 150 gallons of live sand from another tank BUT, it had been in buckets for a few weeks and I had a HUGE amonia and nitrite problem followed by a diatom bloom the red cyano algea. It took about 2 months to settle down. I am sure it is because the bacteria on the sand died and I had anaerobic bacteria and massive waste products to get rid of. All is well now and the 125 is populated and everything is growing well.
So, I guess, the answer is check the parameters but probably you could add them in a few weeks after setting the tank up if you never let the live rock or sand sit without filtration/circulation and go anaerobic live my 125 gallon.
Mike
I live in my own little world. But it's OK, they know me here.