Floating pool liners are caused by groundwater outside the pool coming up to, or higher than, the water in the pool. This can happen during the construction of the pool, when the hole dug is slightly larger than the pool, causing water to be retained before absorbing into the surrounding soil. As the water absorbs into the soil, the pool liner improperly presses against the pool structure, and forms wrinkles. There are several methods of fixing floating pool liners, and the pool liner should be repaired before it causes any further damage.
Press the pool liner against the wall and floor of the affected area of the pool by using a pole with a pool brush on the end. This can only be done if your pool is not yet filled with water. Pressing the pool liner while adding water to the pool at the same time will prevent wrinkles from forming in the pool liner.
Remove wrinkles in your already full pool by using a toilet plunger. Plunging around the wrinkles will spread out the pool liner in that area, and remove the wrinkles. Do not plunge directly on the wrinkles, but above, below, and around them. This only works if there are a few small wrinkles in your pool liner.
Install at least two well point lines to pump groundwater out of the pool. One well pump line should be installed on each side of the deep end to prevent the liner from floating away from the wall.