Pure + Simple PURA-25P 25 lbs Ionizing Chlorine Free Shock - There are lots of reasons to love your pool such as long afternoons with your family in the water, romantic midnight swims and celebrating special occasions with friends. Unfortunately, too many pool owners become frustrated with water issues like cloudy water or green water which can be easily avoided with a weekly addition of Pure & Simple Ionizing Chlorine Free Shock. Most pool owners would agree that the most money is spent after there is already a problem and you are trying to "rescue" the pool. This is a multi-purpose product that reduces chlorine usage, eliminates chlorine odors and assures a clean, clear and healthy pool. In short, your pool will always be ready for you whenever you're ready to use it.