I have fought hard water and rust stains forever. I have spent tons of money on products that just would not work. The only thing that would work was a product in which you needed to open doors, windows, and turn on the exhaust fan and scrub, scrub, scrub. I bought Super Iron Out Spray, sprayed it on the tub and within minutes the stains disappeared. You have a life time customer for and thank you for making a product that works and makes my life easier. I cannot say enough good things about this product. I am very impressed and so very grateful to say the least. by: Debbie Spearman