[m463]

That's really interesting.

I read this: https://en.wikipedia.org/wiki/Hard_water

"With hard water, soap solutions form a white precipitate (soap scum) instead of producing lather, because the 2+ ions destroy the surfactant properties of the soap by forming a solid precipitate (the soap scum)."

I wonder if the vinegar helps clear this out.

SLS is a surfactant. I don't know how it all works together.

[b112]

There are loads of additionals added to soap, likely SLS helps too, to combat hardness in water. Most water has some hardness, but mine varies between 20 and 60 grains of hardness, which is quite high.

As you cannot tell the perfect amount of soap to add, unless you know the precise hardness at that moment, water like mine which is variable means a simple thing.

I am simply forced to add 3x the soap of the 'low range' of my water hardness, thus ensuring the clothes are effected by the soap.

Yet with amounts like that, all the soap has a difficult time washing out. Vinegar really helps, as an acid, to nullify the soap and wash it out.

So my target is not SLS in specific, just 'soap is a base, so acid should help get rid of it', which seems to work.

Some organisms cannot handle acid as well, so it may help in other respects.