adding chlorine

[jackinlv]

A local "pool school" class I attended stated that liquid chlorine should be added to the pool at dusk or at night because it would quickly lose potency if added in direct sunlight. This is in Las Vegas where it is sunny almost every day. Any merit to this idea or more poor advice from pool shops??

[PoolDoc]

Sunlight breaks down all forms of chlorine -- that's why you add stabilizer. But the effect is primarily on chlorine IN your pool, not on chlorine as you add it to your pool.

We usually recommend that you add chlorine late in the day, especially when you are adding a large dose, in order to allow the chlorine to work all night before being affected by sunlight. But that recommendation isn't changed whether you add bleach, cal hypo or dichlor!