Warm your 24 ft round inground or above ground pool the chemical free way with this 8 mil solar blanket. Thousands of sealed air cells on the underside capture sunlight and transfer that heat to the water, while the blue top side slows nighttime heat loss and reduces evaporation by up to 90 percent. The 8 mil thick polyethylene construction resists tears and Uv damage far longer than thin bargain blankets.