While swimming this evening my son said the liner was slipping (i.e., moving) under his feet. Is this normal? Putting on googles, I verified that the liner could be moved on the slope leading to the deep end. Note that my water temperature was 86 degrees. I thought it would be next to impossible to move the liner under that much water...also note that my liner is tight to the bottom.
20 x 44.5 single roman end, ~33,000 gallons, 10 feet deep, garrett vinyl liner, Hayward SwimClear Cartridge Filter, Hayward 2 HP Pump, Cirrcupool RJ60 SWG, Hayward 140k BTU Heater, Polaris 380 with Booster Pump