greywater filter

I am looking for a filter of some sorts for greywater. I have 8 fruit trees that I would like to water with the greywater from the shower/bath and posiibilly the wash machine and dishwasher. Everything is uphill from the tress by 18"-20" so it would need to work in gravity feed.
Also does anyone have suggestion for soap, shampoo, dish washing soap and laundry soap that can be used ?

Thanks

Karl

why not just use it as it is..maybe allowing it to run on the surface just a ways uphill from the fruit trees allowing the soil to filter it down to the trees? Maybe put in a bed of perennials above the trees..or around them..i plant perennials under all my fruit trees so the soil is covered but not really in competition to the trees..