Memorial day is just around the corner and I am intent to have my pool to 80 degrees F if the sun cooperates. I live in Williamsburg Virginia, and it was about 80 degrees outside temperature today with full sun hitting the deck. This setup is only temporary to warm up the pool from its winter hibernation. The tube is a 6mil black food-safe polyethylene 1000 feet long. Don’t know how long it will last, and pinholes quickly formed when I kinked it during unrolling, but it was only $50. I realize now that I should probably space the coils out so the deck can see the sun and transfer heat to the individual runs instead of the grouping.