If your water is leaving marks on your clothes this means that you likely have hard water. The hardness of water causes it to interfere with the effectiveness of detergent and leaves a film on the clothing. To remove this film try soaking the clothes in a mixture of one gallon of water and one cup of vinegar. To prevent this from happening in the future, you can add a water conditioning product along with the detergent, or add a cup of borax. It will soften the water and freshen the wash as well.