When filling your above ground swimming pool, it is important to smooth out any wrinkles that occur in the pool liner. You can do this by removing one strip of pool liner coping at a time and pulling the liner up or down. It is a good idea to fill the above ground pool up with about a foot of water (assuming that you have at least four feet of pool wall depth), then make your adjustments before filling it any further. It becomes increasingly more difficult to adjust your pool liner as water level rises. Once the pool is filled, you should cover all of the return and skimmer line openings with cardboard and duct tape, then slide a vacuum hose between the wall and liner. Upon turning the vacuum on, you will quickly see the liner shrink into place.