The liner in your pool is a very durable item designed to give you many years of enjoyment. Proper water chemistry is very important to the life of your liner. While the title of this article is Vinyl Liner Maintenance, the bad maintenance practices outlines here will also cause problems for concrete and fiberglass pools.
When using granular chlorine, if you pour in a cup in one location, it could fall to the bottom and bleach the liner. That bleach area will start to become very thin and develop holes. Your liner will then start to lose water. Broadcast it slowly around your pool and brush off any that falls to the bottom. Be sure to follow all safety instructions found on the label.
if you use chlorine tablets and do not use a chlorine feeder and put them in your skimmer basket, this could cause your liner to bleach just below the skimmer and become very thin and start to leak. You should use a chlorine feeder for these tablets. Tablets will tend to lower the pH and Alkalinity levels of your pool water. Your liner will lose its elasticity if these levels stay low and the liner will become brittle and could split.
You should have your local pool dealer check your pool water on a regular basis so you can maintain proper levels. Test strips are also available for you to use if you are not close to a pool store. We have stories of customers who have their original liner in there pool from over 25 years ago. You may also be able to do this with proper care and water chemistry.