After doing some research, I finally figured out that my fiberglass pool is the Pacific model by San Juan Pools. According to their website, the gel coat is NPG/ISO (Neopentyl Glycol Isophathalic), also called ISO/NPG from CCP Composites. A search for Neopentyl Glycol shows the chemical structure as C5H12O2, so it would seem that it's Carbon, Hydrogen and Oxygen and I don't see anything about Calcium, but then again, what do I know about chemistry!
My question is, is this the type of gel coat with calcium in it where I need to keep the CH up to around 220? Or is this the type where I don't need to worry about it and I could use much lower levels (such as when filling with soft water)?