what did it come out of and what do you have? I have 20k 150w halides so most every frag I buy will have come from higher lighting and only have 1hr to 24hr transit time so I have never found it neccessary. If you have strong lighting (250w XM 10k for example) move it up a little each week. this is easier done with a frag rack.
Came from a LFS not sure of the light they have but mine is a 6 bulb T5 with individual reflector. I kept it at the bottom for about 3 days and now have it a bit above the half way point of my tank.