John,
Prior to going away it would not hurt to bring your Cl up to shock levels. The SWG, once adjusted properly, should maintain a constant level 2-4ppm anyway but the shock would protect in case of a storm, junk in pool, etc. If the SWG is not up and running and/or your CYA levels are low you could alternatively use a floater with some stabalized (dichlor/trichlor) tabs. I am sure more detailed info will follow. Thanks