Type of filter to be used for recycling the grey water.

Hi, I am new to the forum. Can anybody tell me which filter we should use for recycling the grey water. We are planning to recycled the water collected from residential buildings. We will use this water for cleaning automobiles or sort of things. May be a small business can be develop from this recycled water. Can anyone guide me for the type of filter we should use for recycling the grey water?