Biodegradable washing powder



Dear OSG community,

Can anyone recommend a tired and tested biodegradable washing powder that can be used in a grey water system to water the garden?

I have heard that it is a good idea to add vinegar to the grey water in order to increase the acidity levels before using it on plants - is this necessary?

Any advice or tips would be much appreciated


Hi Jani
I think most brands work - I’ve tried Bloublommetjieskloof products and whatever Organic Zone in Lakeside stocks. I think even normal brands would work. The important thing is to try and keep the amounts low to not shock the system. We don’t need to add as much as the label say - try a quarter of the recommended dose and see how it goes.

I’m not sure about the vinegar. but it sounds like a good idea. Also the vinegar has some carbon in it that will help the soil bugs absorb the nutrients - a good thing. As this post (link below) says, get mulch - anything carbon-ey would work, leaves, wood chips, bark, compost… it conserves moisture and helps buffer against the stuff in the greywater.


Hi Jani,
We have been using Pro-Bac ( - PROBAC uses ‘Beneficial Bacteria’ to actively biodegrade dirt in the process of cleaning, eliminating chemical and dirt transfer to the environment.
I assume that would work for a grey water system just fine.
Problem with the product is that it is not consistently available in shops. So we buy in bulk from the website and refill our smaller bottles with the bigger 5 liter bottles. We have made it a company thing, where staff can refill their home bottles at the office, to promote green cleaning at home. I really like the product.


Hello Jani
We use Earthsap which works pretty well for very dirty stuff and when less dirty, a bio wash ball which is no soap at all. I dose the grey water system with Probac Grey Water Treatment to boost population of microbes in the system about once a week. Also important to consider what plants the water goes onto, grass loves soapy water, fynbos less so.

Keen try to try Marloes’s suggestion. I didn’t know that probac made a laundry soap.



Thanks so much for the tips! I will give Earthsap and Probac a try. @Donne_A great idea to treat the grey water too.

@marloes, what an awesome initiative allowing staff to refill at work!