My pool is:
13,500 gal gunite
basic White Plaster
1/2 coping is flagstone
1/2 coping is moss rock (like the waterfall)
Aquarite Salt System
2~3 foot waterfall
Bubbler on Tanning Ledge

My current chemistry is (using a Taylor 2005):
Water Temp: 84-ish (F)
pH: 7.6
Alk: 110
Cyanuric Acid: 70-ish
Total Cl: 10
Free Cl: 10
NaCl: 2900

Ca Hardness is 625
(the Ca of the fill water is 250)
I keep a history of my pool chemistry and according to the spreadsheet, my Ca was at 500 in April

I control my pH/Alk with about 1 ~ 2 qts of Muriatic dropped once a week to bring the pH down to 7.2. I aerate about 10 hours a day, every day (whenever the pool is on, so is the waterfall and bubbler, and it's on about 10 hours a day).

So,

Is 625 a 'bad' Ca Hardness level?
My worry is it will continue to raise and me at 800 by the end of summer.

Why does Ca levels raise?