I went into my local pool store to pickup a bottle of polyquat for my upcoming closing. Just for giggles I brought them a sample of water to test. They want me to add more calcium to help protect the vinyl liner of my above ground pool. They claim that without enough calcium in the water, the calcium in the vinyl will be leached out causing it to become brittle and prone to cracking.
Do vinyl pool liners have some sort of calcium additive? Or are they just concerned with corrosive properties of soft water? My calcium is currently at 175. This isn't something I need to be concerned with, right?
They also warned me about buying powdered shock (which I don't use) from big box stores because they use stabilizer as a filler and claimed that theirs does not contain any CYA. I thought I was about to catch them until I read the label. They were selling calcium hypochlorite. So I at least feel good about that. With low calcium levels, I was going to try to calculate the cost of cal-hypo vs. the bleach I am currently using to see which is the most economical. If it works out, I might use the cal-hypo next season.