This might be obvious to many of you but I would just like to share with you the power of vinegar. Plain old vinegar. We recently moved and my sweet mother-in-law helped me clean up our home. I could not get the bottom of the tub clean. Hard water! We let the tub soak for a while and presto. It was spotless. Vinegar also works on your shower heads. Just put it into a sandwich baggie and hang it on the shower head. Your water will come out great after that!