A cheap vinyl liner will last 3 years. You can purchase pools nowadays from places like Walmart. And believe us, you get what you pay for. A good quality vinyl liner can last 7-10 years and should cost you a few thousand dollars.
You can make your liner last longer by getting the right people to install it. Should the liner tear upon installation, your pool company should replace the entire thing at no cost. Also, adding the right amount of sanitizing chemicals to your pool will extend the life of the vinyl liner. Over-chlorinating can cause your liner to fail faster than it otherwise would have.
Your dog might like a nice refreshing dip in the pool, but those claws of his can cause quite a bit of damage to your liner when he’s climbing out of the pool. If you have a dog who likes to swim, make sure you have shallow steps where he can walk in and out from as he pleases, instead of scrambling up a ladder.
Never bring sharp objects into the pool. I know your kids might like to bring all their toys into the pool, but make sure to sort out which ones are “pool-safe” ahead of time so that you don’t end up with a $2,000 repair job and a month without a pool!
You can purchase a simple DIY patch kit for minor repairs (both dry and wet patch kits exist) They will contain small vinyl circles upon which you apply an adhesive (usually supplied in the kit). Always follow the instructions on the kit. If the rip is underwater, no need to empty the pool, just put on your snorkel gear and dive in. Pre-glue the back of the patch and place it evenly over the tear, making sure to smooth it down completely. You can still swim in the pool, but remember to follow the instructions on your kit before touching it again.