"HTH stabilizer, 4 lbs., helps to protect and extend the life of chlorine in swimming pool water. It slows the loss of chlorine caused by sunlight. Use this product if sunlight makes it difficult to maintain the correct chlorine level._x000d_ "_x000d_ _x000d_ Extends chlorine life _x000d_ Sun defense for pool water _x000d_ Compatible with Salt Systems _x000d_ .
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