I have read for some time on letting the water settle theory and to be honest did believe there could be something in it.
But i am at present building a house for a race horse owner which the stables are already built,and decided to ask the vets and the stable hands if they allow the water to stand for 24hrs as i have heard this is common practice in most modern stables.There reply was that they have never heard of such practices and that it was a lot off nonsense,just to add this is a major stud with millions invested in the finest race horses.So since having this conversation i have to say i no longer believe the water settling theory.