Despite what students may think, baths are not self cleaning. Here is how to remove nasty rings. Everyday, get in the habit of wiping down the bath after each use and limescale won't have the chance to build up. Plastic or acrylic baths scratch easily, so steer away from abrasive cleaners. A gentle wipe over with a mild bathroom cleaner and a soft cloth should be enough. If you find yourself with a particularly dirty bath, try filling it with warm water, chucking in a scoop or two biological washing powder and leaving overnight. Enameled baths are slightly tougher than acrylic but are not totally scratch proof either, so leave the scrubbing brush alone. Stains on the enamel can be treated with a paste of bicarbonate of soda and a drop of warm water. See below for limescale treatments. Cast iron baths, take great care with these. Always test new products on an inconspicuous area before sloshing it all over. Avoid products with anti-limescale ingredients as they may cause the enamel...