Oh yes, one more thing, when you have the sand curing in the saltwater, you need to "feed" it. Some say flake food, I used little pieces of mysis shrimp left over from feeding my clownfish. You could always buy some frozen cubes and just use one for your sand.
What this does is introduce bacteria to the sand. Fresh dry sand in your tank makes a big huge cloudy mess. The bacteria coat the sand particles, helping to weigh them down. Plus you are building your base of beneficial bacteria which your tank will need.
Do a search on Curing Sand and you will find the detailed information, one of them even had a picture of the bag of sand which helped me to be certain I was buying the right kind.
Oh, and if you come to Wisconsin, the sand costs $7, apparently if you go visit NJ it'll be cheaper