Low calcium levels, plasticizers in vinyl liners, leaching cobalt from fibergalss?

[waterbear]

Thangs guys! I was tending to that direction myself but this is the first "pool store guy" that I have come across that really seemd to have a handle on the chemistry and was not just spouting Maufacturer's rhetoric. He even acknowled that laundry bleach is just as effective as liquid chlorine and he stated that borax was better than soda ash for pH control since it won't raise carbonate alkalinity! The handout that he gave me had someithing similar to Ben's "best guess chart" for CYA and FC. That is why I questioned what he said on here concering calcium in the first place! Almost everything he said was good info.
I've spent about 9 hours researching on the 'net' and have found nothing to back it up. If anyone ever comes across anything about this one way or the other I would be interested in hearing about it.

[CarlD]

Dave reminded me: Etching in the dishwasher not only takes place at high pressure, but at very high temperature as well and that usually makes most chemicals more reactive.

[waterbear]

I just found some info on the San Juan Fiberglass pool website that is interesting concerning this topic. I own a San Juan Cocoa Beach model. Their maintenance manual (downloadable from their website) states:
"Calcium Hardness (C.H.) is the relative hardness of your pool water, and is measured in P.P.M. If the water is too soft, it will be aggressive and erode pool equipment such as heaters, ladders and even the gel coat finish. If the water is too hard, deposits will form on the pool equipment and finish. 300 to 350 P.P.M. is the proper hardness for your San Juan Pool and should be checked monthly."
One of the largest manufactuers of fiberglass pools recommends CH levels of 300 to 350 ppm to help protect the gelcoat if I read that properly. The maintenance manual also recommends ALK between 70-80 ppm. I am going to check the other major fiberglass manufacturer's sites to see if they say anything similar.
Edit: Just checked Royal Fiberglass pools and downloaded their care manual. It recommends CH between 200-400 ppm and states that low Ch levels can cause "Distorsion of pool finish" and "Premature aging and shorter life expectancy of the gelcoat finish"