dunno where you got that raising the salt thing from, but you should have a tank 3/4 full of proper sg water (1.023-1.026) ready when you buy your rock (assuming you're using LR) with a bit more in a bucket nearby. Bring the rock home, aquascape on the glass bottom, setup powerheads/heater/hardware, fill in with sand, turn on hardware, top off the rest of the way from the bucket, wait for cloudiness to subside...