Have you read a book yet on the subject? You'll save yourself a lot of time asking simple questions if you do a little research before hand. Not to mention confusion and frustration...
This article recommends a few good ones. Not listed is The Reef Aquarium Vol 3 by Delbeek and Sprung which is my all time favorite. Most other books just brush over the process of setting up a tank while that one goes into some really good detail.
Building a Proper Marine Aquarium Library
http://reefkeeping.com/issues/2008-01/tips/index.php
reefkeeping.com in general is great if you want free literature. All of their articles are indexed here:
http://reefkeeping.com/issues/subject/index.php