[Pil-pc-oceania] for greywater re-use, soap is SALT

[David Arnold]

Hello All,

there has been a bit of exposure of this in the media lately, but it is
worth mentioning again.

One of the main components of soap is *salt* [various Sodium compounds].  If
there is a lot of soap in your greywater, the garden initially looks to have
benefitted from the [salty] greywater that is applied.  As the salt
accumulates in the soil around the plants being watered, the plants will
close off their roots to the salt, and will die of thirst even in a wet
soil.

For greywater re-use information, Lanfax Labs have compared about 50
different liquids, and 50 powders.  See
www.lanfaxlabs.com.au/liquid-sodium.html
Liquid laundry detergents seem to produce laundry grey water that has about
1/10th as much salt as laundry powders.  For laundry powders, and solid bars
of soap, more salt is needed in manufacture to draw the mixture into a
solid.

Basically, especially in dry times when grey water may be a large part of
the garden water supply, try not to use much soap at all, and use a good *
liquid* laundry detergent.

I have usually preferred bar soap because it is so easy to handle and
doesn't require the usual plastic containers, so just use very little of it.

Regards,

David

-- 
David Arnold
Permaculture Designer
4446 Murchison Rd
Violet Town VIC AUS 3669
03 5798 1679
arnold.vt at gmail.com
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