Four signs it is structural
1. You are losing water faster than evaporation explains. Run a bucket test before assuming anything: float a bucket of pool water on a step so both are at the same temperature, mark the level inside and outside, and compare after twenty four hours. If the pool drops further than the bucket, water is leaving the system.
2. A section sounds hollow. Tap along the shell. A hollow note means the finish has separated from the concrete underneath. New finish bonded on top of that separation goes the same way.
3. Rust staining keeps returning in the same spot. That is reinforcing steel corroding inside the concrete. Corroding steel expands, and the expansion cracks the shell from the inside. Cleaning the stain treats the symptom.
4. The bond beam is breaking up at the top edge. The bond beam is the structural ring at the top of the shell. Damage there is not cosmetic regardless of how it looks.
Why this matters in Sacramento specifically
The region sits on expansive soil that swells in the wet season and shrinks in the dry. That movement works against a rigid concrete vessel every year. It is a common cause of shell cracking locally, and it is the reason a repair that only restores concrete, without accounting for what is moving underneath, tends to reopen.
What a proper repair involves
Cutting back to sound concrete on all sides. Exposing the reinforcing steel and cleaning or replacing it where it has corroded, because rust left in place keeps expanding. Rebuilding with material that bonds to the original shell, then blending so the finish can go over it as one surface.
It is the same trade as building the shell in the first place. That is why it is not a finishing job.
The order that saves money
Drain, inspect the exposed shell, identify the cause, repair the structure, then resurface. Doing it in that order costs one mobilisation. Doing it backwards costs two, and the second one is the same price as the first.