Helpful information about your pool.
First of all, Salt water pool's in comparison to a fresh water pool, will degrade at an increased rate due to the salt content in the water. The salt water allows the formation of "Osmosis" which is easily noticable as a raised bump on the inside surface of the pool. Once your pool reaches a certain age, if you used salt for the life of the pool, The gelcoat will break down and allow the transfer of salt through the gelcoat into the fiberglass which in turn creates Osmosis.
Gelcoat can be worn through COMPLETELY! This exposes the raw fiberglass behind the gelcoat, causing fibers of the glass to slowly fray and release into the water of your pool!! If you have exposed fiberglass DO NOT SWIM in the pool, It is a major health risk for you and your family.
Ground water pressure can cause your pool to crack and break! If someone has told you that your pool will pop out of the ground if you empty your pool, They are completely wrong. A fiberglass pool will break before popping out of the ground. If there was a chance of a pool popping out of the ground you will find that those cases are CONCRETE pools. In any case removing the water out of a pool is NOT advised in any cases.
No matter what it is a matter of time before your gelcoat will wear through and the pool will need to be Re-surfaced. It is reccommended to have your pool re-surfaced every 8-10 years. This will extend the life of your pool and keep it looking fantastic!