If you have a standard above ground pool then there is a very good chance that your pool uses a liner.
In many cases this can be a huge advantage because you will not have the rough cement that can cut your feet that many cement pools have.
For a cement pool, it always has to have the calcium hardness at the perfect balance or it will degrade the pool even faster.
That is why a liner for a pool can be such as huge advantage.
That being said, liners do have to be replaced after heavy use.
However, if you go with a higher quality and more durable liner then you should not have to worry about replacing it for years and years to come.
Replacing a pool cover can be quite a chore and takes a significant amount of skill so it is much better to take care of the one you have.
In addition, a quality pool liner is not cheap.
Expect to spend $400 or more on an 18 foot round pool and the cost will go up significantly for every foot after that.
Pool liners are especially vulnerable to sun damage, chemicals, and algae.
You need to make sure that you cover the pool whenever you are not using it if that is possible.
If it is not possible, understand that you are going to need to spend more to get a UV resistant pool liner.
In addition, you will need to make sure that your pool always has the chemicals as balanced as possible.
An excessive pH level can cause the pool liner to degrade.
Algae will grow if you have too little chlorine or if the pH level is too basic so make sure to keep your pool balance to prevent algae.
Algae can stain your pool liner and it can be very difficult to get rid of.