Sometimes mistaken for fecal stains, stubborn brown streaks on toilet-bowl interiors are actually rust stains caused by an abundance of iron in well water. Exposure to oxygen causes iron particles to attach themselves to bowl surfaces and form stubborn brown scale. Besides their unpleasant appearance, rust stains make everyday toilet cleaners ineffective. Alkaline cleaners and chlorine bleach actually intensify rust stains. Remove brown rust streaks from your toilet bowl using acidic solutions.
Twist the toilet's shutoff value, located behind the toilet, clockwise to shut off water flow to the tank. Flush the toilet to drain water from the bowl.
Mix 1/2 cup borax with 1/4 cup lemon juice in a container. Stir the borax and lemon juice into a smooth paste using a disposable spoon.
Spread the homemade paste over the brown rust steaks using the spoon. Lit it sit for 30 minutes.
Dampen a nylon scouring sponge with water and scrub the homemade paste into the brown rust streaks. Rinse the sponge and use it to thoroughly rinse the paste from the toilet bowl.
Examine the toilet bowl for remaining brown streaks. If rust lingers, open all windows in the area to provide ventilation and put on rubber cleaning gloves.
Spray the brown rust streaks with a commercial toilet cleaner -- one that contains hydrochloric acid but not bleach -- according to manufacturer's directions.
Scrub the brown rust streaks with a toilet brush until they are completely dissolved.
Twist the toilet's shutoff value counterclockwise to turn on water flow to the tank. Pour 1 gallon of water into the bowl and flush to rinse away the commercial cleaner.
Substitute an acidic solution of one part oxalic acid and 10 parts water for the commercial toilet cleaner.
Chemical toilet cleaners are caustic and toxic. Do not splash the cleaner out of the toilet.