Just purchased a house with a pool and am trying to learn the basics. I have a multiport valve that is connected to my pump. I want to backwash my sand filter but am unsure which position my valve should be in. I've attached pictures. I have read that 12 2 4 o'clock positions on some other threads, is that rule of thumb constant on all multiport valves because there is writing on it that says 'Filter' in blue. Its currently in the position in the picture as that's where it was when I purchases the house a few weeks ago. I did notice if I placed the handle over the 'Filter' my suction vacuum seems to have more power but my skimmer doesn't seem to work. When I place it back in the position as pictured, my skimmer starts sucking with more power and my vacuum goes slower. Is this normal?