I think he meant he killed the bloom in 2 hours by hammering it with chlorine.

I go with 12 mil clear covers. All covers die in 3 years and the warranty is ONLY for the seams, not the bubbles, so the warranty is worthless. If I cannot get clear, I get clear blue. But I'm done wasting money on the heavy 16 mil covers just to have THEM die in 3 years, too.