I have a 15x25x4 above ground oval pool; used tablets in the past for chlorine, now using TFP method. Live in southern NH and wondered about the opening/closing timing. I don't want to wait until the leaves start to start closing, but have heard from people in the northeast that wait until November! I am also concerned that the chlorine will last until I open it in early May. The tablet method has a floater with chlorine tablets in it to slowly dissolve and keep things sanitary over the winter/early spring. Do I have to continue adding chlorine in the fall and again in the spring before I open it?