Turn on the pump and lock the pause control on the water valve to pause on that station. The weight should come up to a point that you can fish it out. If I won’t come out easily then take a metal coat hanger and cut it so you can bend it in the middle and then make two short bends on the ends about ¼ to 3/8 long. Squeeze together and place it in the center of the weight and let it expand so the two bent ends catch the bottom of the weight. Hopefully that will allow you to pull the weight out of the pipe.