There are several techniques which can be used to clean bathtub rings, leaving the tub sparkling. Once rings have been removed, it is a good idea to get in the habit of cleaning the bathtub regularly, to ensure that bathtub rings do not get a chance to build up again. Encouraging users of the bathtub to rinse out the tub after every use can also be advisable, as can telling people in the house to clean bathtub rings as soon as they notice them.
Before cleaning bathtub rings, it is important to know which material has been used to construct the tub. Enamel, porcelain, fiberglass, and acrylic are all common construction materials, and they need to be handled slightly differently. For example, enamel and porcelain can both be cleaned with mildly abrasive cleansers, while fiberglass and acrylic need to be handled gently to avoid creating scratches which will attract dirt and soap scum.
In the case of enamel and porcelain tubs, the tub can be rinsed out, and a paste of baking soda and vinegar or baking soda and lemon juice can be applied to clean bathtub rings. After the paste has had a chance to soak for 15 minutes, it can be scrubbed away, lifting the bathtub rings off along with it. Mildly abrasive powdered cleaners are also available from the store, and they can be used in much the same way. To add extra shine, the tub can be wiped out with alcohol. A weekly swabbing with bleach or alcohol should prevent the recurrence of bathtub rings.
More fragile tubs made from acrylic and fiberglass need to be cleaned with liquid cleaners and soft sponges or cloths, as abrasive materials will scratch. Detergent can sometimes lift bathtub rings away, as can alcohol or vinegar. For stubborn bathtub rings, it may be necessary to use a commercial liquid cleaner designed for bathtubs which is left on the tub for half an hour and then wiped away. Some people also have success with dryer sheets, which can be moistened and rubbed across the bathtub rings to erase them.
Effective bathtub ring removal sometimes requires some serious elbow grease, especially in a case where one is trying to clean bathtub rings which have had weeks or months to settle into the tub. In the case of deeply embedded rings, multiple passes may be required to get the rings out of the tub, and the tub may have become stained if the rings included rust. While it may be tempting to use a harsh abrasive or pumice stone to clean bathtub rings, these fast-acting cleaners will also scar the tub, creating a problem in the future.