High Alk, High CA, Zero Cholrine in a pool with limestone bricks

Hi all,

We just bought a beautiful house with a beautiful pool, and I fear we are ruining it! We get so many differing suggestions, and I thought I would post this to the group. We have a 10K gallon concrete pool with limestone edging - the limestone has not been treated and there is notable erosion directly into the pool water. The Calcium Hardness (CH) is high at 600, CYA is high at 150, Total Alkalinity (TA) is high at 130, and free chlorine is zero. I suspect the high calcium is (in part) because of the limestone erosion into the pool, but we can't seem to raise the chlorine levels. The pool warranty guy describes the pool as "over stabilized" and said that we need to drain 80% of the current water. The pool store lady suggested muriatic acid with liquid chlorine. Online forums are inconsistent in their responses. Please help! What should we do??

Thanks,
cspsyyd