[Greenbuilding] (sources on) graywater basics?

[Reuben Deumling]

I'm interested in ideas for turning ~20 gallons of domestic graywater/day
into irrigation quality water for a backyard garden (April-September only
for the time being). I don't need much storage. I'm envisioning directing my
graywater into a barrel full of sand which issues into a "rain barrel." I
think I've got just enough height for this to work.

Things to avoid, keep in mind? Primers, websites?

Thanks very much.

Reuben Deumling