When I rub the walls of our fiberglass pool, a white chalky substance comes off on my hands. When I brush the walls, it clouds up the water. I called the manufacturer and was told that it was caused by too low calcium, too high PH, and high chlorine levels. They recommend a calcium level of 350, PH of 7.4, and chlorine level of 1-3. This year, I've been keeping my chlorine at 5, calcium has been around 150-200 and PH tends to stay around 7.6-7.8. I was advised to increase my Calcium to 350, be more diligent about keeping PH lower and decrease my chlorine level to 3 or lower. They recommended that I use a calcium scaling product to remove the scale. I was getting ready to close the pool in a few weeks so I'm wondering if I should raise the calcium level now and use the descaler product before we close, just add calcium now and wait to use the descaling product in the spring, or just close with the calcium levels lower and postpone doing anything until spring. Will the calcium scaling get worse or damage the gelcoat if I close the pool with low calcium levels? If I don't remove the scale, would bumping up the calcium level to 350 preserve the gelcoat over the winter? I was told that the calcium scaling product might take several months to work and I don't have much time since we plan on closing in 2-3 weeks so I don't know if it is worth trying it.