New Reef Setup...help!

Hello and thanks up front for all your facts on reef systems! I'm
starting to set up a new reef tank, 40g. I plan to have 20lbs live sand
and 20 lbs CarbeSea Florida Crushed Coral. I have a 10g wet/dry with my
homemade skimmer.

I have only water in the sytem now, testing and getting familiar
with the sump and how it all works. I have been spending about 8 hrs a
day reading here and other reef forums I have found on the internet-
there is so much to absorb!

My really important question is can I use my city water after its
been circulating for awhile? I mean I have not finished all my research
yet, books and internet, and plan on another 2 months of reading...

What I really want for my tank is the small creatures from the
live sand from the Florida keys. Should I also add the stuff "GARF
Grundge"?

Any input is greatly appreciated!!!!

PS: my LFS has the live sand also, should I get it there? I'm
Jacksonville FL