Need help with marine salt -setting up a new tank-

[snow1]

HI all, this is my first thread on this forum and I need some advice. So advise me.
Tomorrow I'm getting my 175g salt tank. I'm only going to be saving enough water for the live rock. I have a 160g bucket of saltwater salt. Some say that if I add the salt into the tank with prime while I'm filling the tank up it will cloud it and it won't be good? Why is that? I know that when it comes time and I'm doing a water change I should mix the stuff a day before.....well I now don't have a day.
So how would I go about doing this? Should I fill the tank up and every 2 mins add a cupful of salt to the tank? OR should I add half the bucket when I'm starting to fill and tank and the rest after I'm done filling the tank. I don't really know how to go about doing this so any adivce on how to add salt to this tank when I'm filling it up? Much tank-u.