I have an intex 12 ft pool with the inflatable ring. It has a leak but I can't find it. I fill the ring which has a small leak somewhere because after about a few days u can tell it has lost air but I also have to fill the pool again. It loses water to a certain level (about 24 inches) and then stops. It's good for about 2 days. Have looked for wet spots and find nothing. Any suggestions. I assume the leak has to be above or at the 24 inch mark?