The following problems with Back Wash Valves can cause your water to become cloudy because the water pulled in from the pump is going back into the pool without being forced through the pool filter first.

1.) You have a torn, damaged, or "Pulled Loose" Spider Gasket (Dial Back Wash Valve)

OR

2.)  You have "missing" or Torn O-Rings (Push-Pull Back Wash Valve) (Click HERE)

        If it is a Push-Pull Back Wash Valve, you can attempt to pull it apart, inspect it, and replace and Lube any Damaged O-Rings. There is usually either a threaded plastic color at the top of the valve, or two screws at the top of the valve. (NOTE: DO NOT USE VASOLINE on ANY rubber parts or O-Rings. Vaseline EATS Rubber. Use an appropriate “lube”, not sealant. I prefer silicone based “Lubricants”. They last longer.)

If you have a Dial Valve, Call a repair person. Hopefully you will get someone who knows what they are doing.   There is no quick, OR easy repair for dial backwash valves.