Next time your pool professional shows up with liquid chlorine in the back of his/her truck take note where it is stored.
Liquid chlorine should be stored in a cool place, shaded from sunlight. At 78oF (26oC) the available-chlorine level in a jug of liquid chlorine will drop from more than 12 percent to 9 percent in one day. At 93oF (34oC) the available chlorine level will drop from 12 percent to 9 percent in just 2 hours.
Aeration and sunlight can destroy part of the available chlorine when pouring it into the pool. Pour it into the pool with the jug as close to the water surface as possible. One to two percent of the available chlorine can be lost by pouring the liquid from only 4 feet above the water’s surface on a sunny, hot day. Common household liquid bleach is sodium hypochlorite, at around 1.5 percent.
Adding chlorine at a return jet or in a manner that mixes it with the water reduces the chlorine loss. If you stand in one spot while you pour the chlorine, the sunlight can begin to destroy the chlorine before it has had a chance to mix with and be protected by the Cyanuric acid (conditioner). You can lose 1 to 2 percent of the available chlorine if you don’t “walk it around or mix it at a return jet.” Chlorine is more effective if added when the sun intensity has decreased.
My recommendation is always try to use dry chemicals when possible. For those that purchase liquid chemicals at big box stores like Home Depot, Lowes, Wal-Mart, etc. consider that most of these chemicals are stored outside. If you live in a climate that gets hot (like here in Vegas) you may want to consider purchasing your chemicals at a pool store instead where the chemicals are stored indoors.
Red Square Pools
Persident / Founder