advise on what to put in containers to filter/treat grey water

hey folks!

i have a mobile home with one occupant (me) and the woman visits... want to treat the grey water from mobile

ok so i have two containers measuring 64 x 26 inches with a depth of 23 inches. with these two containers i hope to build a grey water treatment system. unsure of what to put in these containers.... stones for micro bacteria? plants? any help advise would be great... the water coming out the end of this system will go into a container in my ploytunnel via a submersable pump for feeding plants. so its a given that only eco friendly/ natural soaps will be used

http://greywateraction.org/

http://www.oasisdesign.net/index.htm

Try reading from the sites above and see if you can find some ideas.

Here's a page with a couple diagrams of different systems: http://www.letsgogreen.com/greywater-recycling.html

The mulch pit in the soil system uses mulch, the system in the container uses gravel. A coarse gravel should work in your containers. Cattails and Canna are two good choices for plants, both are very hard to kill. You also want to have a bed, probably in the soil, to which the treated water can overflow, this can be planted to just about any plants that grows well in the climate, or it could be a fruit tree.