Natural Chemistry Hassle Free Start-Up / Closing Kit provides pool owners with a convenient, one-step treatment to prepare your pool for opening or closing using an all-natural formula. Hassle Free Start/Close Kit's natural enzymes stay in your pool all winter long keeping water clean and clear, preventing water line and scale build-up, preserving mesh and vinyl pool covers, adding no phosphates, and greatly reducing normal prep work for opening a pool in the spring. Best of all, it will give you peace of mind during the winter shutdown, which you cannot put a price on.