On Tue, 21 Mar 2006 22:34:36 +0000, Nigel Molesworth
wrote:

I can assure you that soft water does not require as much detergent
for the same cleaning power. Part of the detergent is used up in
softening the water.

The cleaning power is exactly the same! The effect is purely
psychological, due to the increase in "bubbleability".

Ask on one of the chemistry newsgroups.

sponix