We have an inground pool. Right before we opened the pool, we noticed that our cover had dropped. After removing the cover, we had noticed we had lost quite a bit of water. We also noticed that the light we have in the pool was half filled with water. We re-filled the pool and started the pump. Everything seemed fine until recently. We noticed again we are still losing water, about half an inch a day. We kept the filter off for 12 hours and lost half an inch, and ran it for 12 hours and lost half an inch. I noticed after backwashing the pool, we have air coming out of the jets. The pool is just 4 years old, and the installer of the pool is pretty much blowing us off. Any help will be appreciated.