Liner??
Can't you shock the water to get it clear?
Maybe its a midwest thing, but liner pools (even 100% inground) are common. Concrete pools crack from frost heaving. The bottom is shaped with packed sand, the sidewalls are 3 to 4 foot panels, usually stainless steel, bolted together. Then a vinyl liner is hung from top edge of the sidewall, countored to fit the sand. Done properly it looks like blue concrete. Takes some skill to lay it in without a wrinkle.
I built them in high school days. A sharp toy like a metal boat could punch a hole in the liner, particularly if it sank from the deepend titanic style. But the liners are pretty tough. Leaks were most common at water level where toys punch in, or near the drain where a strain might occur if the sand was not tall enough and let the liner stretch to the drain, where screw holes are. Or the underwater light, again screwhole fatigue, or the skimmer. Seldom in the liner at large, they generally do not have seams. (IIRC)
We would find leaks (or the boss would) by using scuba gear and a tool that would emit a die, he would swim around in the pool with the die tool, when it would flow out you'd have your leak. They make underwater patching kits, it did not require draining the pool. Though if its at the drain, it might.
OP lives in FL. Probably not a liner pool.
