nah i wouldnt necessarily say the liner needs it, I am just in atlanta here and the ch out of the tap is 80 ppm, i tend to get it to about 250 in a gunite pool, 150 for vinyl and fiberglass and 150 for spas. I wouldn't say it affects the liner but I did look on some major manufacturers of liners and they said to keep it 100-200. I know most places in the country arent gonna be 50-80 out of the tap like we are here.