I would -- just to be sure that I got off to a good start. If you haven't added sand or rock to the tank yet, empty it completely, clean it thoroughly (vinegar and RODI water then a good rinse in RODI to make sure all of the vinegar is out)
Here is a link to good RO/DI units (I like the Ocean Reef+2 unit)
http://www.thefilterguys.biz/ro_di_systems.htm
Pick up a good TDS monitor as well.
If you already have put sand and/or rock in it, siphon the water out and replace with new (RO/DI) saltwater and hope for the best. I'd also run carbon for a few weeks during the cycling process then a large water change. Copper and Silica are a couple chemicals that may be of concern. I'm sure others will have varying advice.