Tips for keeping swimming pool vinyl liner in top shape:

 Keep the pH between 7.2 and 7.6.  Chlorine works better when pH is maintained at proper levels.   This will also result in the water being more comfortable for swimming.    Low pH can cause the liner to wrinkle up or become brittle.  High pH will cause scaling and calcium build-up on the liner and it may be impossible to remove.

 Maintain the free chlorine residual between 1.5 and 2.5 ppm.  If it dips below that the liner may get stained due to algae and bacteria growth.  If it goes above 3.0 ppm, the liner may absorb water and develop unsightly wrinkles.

 Total alkalinity should be between 80 and 120 ppm.  This will help keep the liner from getting dry and fading.   If this is not controlled you will have premature breakdown of your liner.

 Routinely stabilize the pool with cyanuric acid in a range between 50 and 100 ppm.  A level below 50 ppm combined with low pH and/or high chlorine can cause wrinkles.

 Keep calcium to at least 200 ppm to avoid corrosion.  If it gets higher than 500 ppm, scaling may occur.

 Allow one chemical to circulate through the pool system before adding another.  Doing this reduces the risk of bleaching caused by certain combinations of chemicals in high concentrations.

 Clean the waterline with vinyl-liner cleansers, which are available from pool retailers.  Do not use common household cleansers as they may abrade the liner.

 When closing the pool, circulate the pool's water for several hours after final addition of chemicals.  This helps avoid bleaching caused by chlorine settling in the deep end.

 Clean and vacuum the pool thoroughly at the end of the season and cover with a dealer - recommended cover. 

 As is the rule with any pool, never drain the pool completely.  Empty pools increase the risk of getting wrinkles or shrinking vinyl liners.