I called Taylor today to finally ask them why they recommended a minimum CH level of 150ppm for a vinyl pool. I spoke to two people before finally being directed to a third. He said that even if the calcium didn't come from the vinyl, the water would try to pull it from somewhere. I said that most everything is PVC and fiberglass - in that case, why the calcium? If water is getting onto the pump motor, you're in trouble regardless of the calcium levels.
His two responses were that it could pull calcium from behind the liner (what?) and that low calcium levels made it difficult to balance pH and Alkalinity. Is there any truth to this? If not, the misconceptions must come from somewhere - does anyone know where?
Thanks any who take the time to answer, as always.