Oh, I understand that there are many difficulties in setting up a test protocol. Even if we could give 100 people liners made by two different methods and test them over 5 years you would have trouble isolating out meaningful results due to variations in water condition, air temp, exposure to sunlight, levels of chlorine, pH, etc, that don't allow you to control for high and low calcium water. For the moment all we have is the testimonials of owners who have had vinyl pools for years with low calcium levels. This is, at best, very poor data, because we don't know what our population is, and we can guess that our sample is probably skewed. That's my side of the fence, the clinical trial issue.

Your side of the fence is establishing a mechanism where low CH can be shown to degrade various vinyls while high CH doesn't degrade the matched vinyl samples. You know, the chemistry side that I don't understand.

In the meantime, our anecdotal information tells us that CH for vinyl is...not proven to protect it.

Carl