http://www.reefkeeping.com/issues/2004-05/rhf/index.php A article I love posting from RHF.
this should give you a good starting point.
first make sure you mix your salt to the salinity the manufacuturers have designed.
That way your chemicals balance out. Salinity, temp., and PH are very importantant.
After you get salt mixed. The three common things tested are calcium, alkalinity, and magnesium. They all are very important. But first read the above and set goals. Hope to talk to you soon. Meeting in Kennewick, really soon....