Floating: A liner is held down by the weight of the water in the pool. Occasionally like after a big rain or if the water in the pool is lowered the ground water can become heavier than the water in the pool, causing it to "float" or push the liner away from the walls. Its not hurting anything in this state and it will go down once the ground water goes away but it typically won't go back perfectly and you might end up with wrinkles in the liner. The liner is easiest to move while its still floating, so you can take your pool brush and gently try to push the liner back to its corners if you can get the water behind the liner to move. Sunledges and steps can easily shift if you don't keep enough water on top of them. Keep at least 6-12 inches on them at all times.
Wrinkles: Like we just talked about wrinkles form when the liner gets shifted. Some can be removed if the liner is pretty new but is a process you'll want a professional to take care of. You can also get wrinkles from chemical damage. Anytime you're adding a grandular product, don't just dump it in and let it sit in one place. Thoroughly brush until its disolved or predisolve in a bucket before hand.
Stains: This leads into the next topic which is stains. Chlorine can bleach your liner very quickly if you let it sit in one place. Always predisolve cal-hypo before adding it to a vinyl lined pool and then brush any left over grandulars right away. Mineral and organic stains can also form but can be taken care of with different chemicals. Read our stains articles for more information. Its very important if you have an AUTOMATIC COVER to regularly open the cover. Automatic chlorinators will continue to treat the pool and with the cover closed the gases have no where to go. This can hurt your liner and cover!
Out of Track: Occasionally a liner can slip out of track in some areas. The older the liner gets the harder it is to stretch back into the track because it looses its elasticity. Never pull too hard on an old liner, it will tear. You can add liner lock to specific areas of the pool where the liner pops out more frequently.
Holes: Even a pin hole leak can cause your pool to lose 100s of gallons of water. Once a hole has been identified you can apply clear patches to repair it.???