You can buy liquid chlorine, or just use plain, unscented bleach, whichever is cheaper in your area. You can pour it into the skimmer, slowly around the perimeter (stirring to eliminate hot pockets), or pour it into the stream from your return--it's up to you. It's fine with a vinyl pool as long as you don't overdo it (see the best guess chart to see how much to add based on your CYA level), and it's fine with the SWG.

You only need to shock it if you have a CC above .5, or your water is getting cloudy....I also shock mine after a large bather load and after a heavy storm, just as a preventative measure.



Janet