I'm wondering if the original poster may have well water instead of water from a public system. We are having trouble with our well and I've noticed that when I add Dawn DWashing liquid to the water with a little clorox it turns dark, dark brown. I'm thinking this is because the water already has a high PH and the liquid makes it worse. ?
tried another tub and added only clorox, which should take the PH in the other direction. Darkest brown. I had also added a bit of clorox to the 1st. tub. Now I know it was in fact the clorox and not the Dawn detergent, which turned the water brown.