Abstract: A lower water chamber is constructed and held in a bladder which underlies the floor of the pool. The lower water chamber constitutes the base of the pool and is initially hollow and empty before being filled with water. The water chamber has a fill opening and a drain opening. The fill opening has a valve for receiving a standard garden hose. The drain opening preferably also has a rigid connection for receiving a standard garden hose. After the water bladder is filled, the user closes the fill opening and the drain to make a closed water bladder. The water bladder is preferably made of a plastic, polyolefin, or elastomeric type of material which is watertight and strong enough to hold the weight of children. The pool is preferably self inflating.