G'day, Have recently read the book "Create an Oasis with Grey Water", by Art Ludwig: https://www.oasisdesign.net/greywater/createanoasis/index.htm (great little book, BTW) My biggest outstanding question is: what detergents etc. are available in Aus that would be compatible with a greywater system? From reading the book, the issue is different to the typical one of cleaners being biodegradable and low phosphate. Yes, we want biodegradable as we'll be watering our gardens with it. But there is a difference between what is harmful to a river or lake or the sea, and what is harmful to plants on land. Greywater is different in that nutrients like nitrogen, phosphorus and potassium are actually desirable in the water - so low phosphate etc. cleaners aren't a benefit here. However, sodium is very detrimental, as it builds up in the soil and can literally kill plants. Most cleaners are high in sodium compounds. In a quick survey of washing machine detergents at the supermarket, they all either don't disclose anything useful or disclose an active ingredient based on sodium compounds. I haven't made the trip to the local health food shop yet, so I'm still hopeful that they'll have something useful there. But I can see some work ahead, emailing the various manufacturers and asking them what they have that is suitable. If anyone has already done this work, I'd be very grateful for your shared knowledge. cheers, Ross.