My wife left the pool cover off in a heavy rain. It added about 2 inches to the pool level. While the water is clear, FC 5.5, CC 0, and everything seems nice and clear, the water just doesn't have that "sparkle" it did before the rain. It used to look really crisp and now it seems a bit dulled. This is so subjective because everything measures perfect and looks right. I cannot measure the "sparkle" or crispness of the water, so I just cannot describe it. The only thing I can think of to get that sparkle back is to shock my pool to 20ppm FC, which is how I got it the last time. Any thoughts on this?