To vacuum my pool, I connect the hose (full of water) to the vacuum head and then to the skimmer pipe after putting the controller into service mode with filter pump selected. With this mode selected, the two-speed pump runs at high speed. There is so much suction the vacuum head tends to stick to the pool bottom. I am wearing out the nylon wheels on the vacuum head and the center part of the head seems to drag along the bottom also. The vacuum head is a standard type with 8 wheels. Should I use low speed on the pump or are my valves adjusted wrong causing too much water to go into the skimmer?