Clorox Pool&Spa Shock Plus is a swimming pool shock that clears cloudy water, kills bacteria, and destroys contaminants fast with its powerful 4 in 1 formula. Shock your vinyl pool without the risk of damaging your liner. Shock Plus doesn't impact pH and is fast dissolving, so you can swim in as little as 15 minutes. Shock Plus is great for both in ground pools and above ground pools. Pair with your favorite sanitizing product such as Clorox Pool&Spa Chlorinating Tablets. Always apply according to label directions. For best results, add to the deepest end of the pool with the filter running. Most customers find the best time to apply this pool shock is during their weekly maintenance.