If your tile turns blue after you take a shower, it could mean that you have copper deposits in your water. If your water is alkaline, containing a high amount of carbonates, it can corrode copper piping. The result is trace amounts of copper entering your home's water supply. The condition often presents itself by turning your bathroom tiles blue. While there is no way to prevent the blue stains from occurring as long as the copper exists, methods are available to help you clean the tile with minimal effort.
Fill a spray bottle with a 1:1 ratio of water and ammonia. Add a squirt of dish soap, and give the bottle a shake. Spray the tile with the ammonia solution, and allow it to set for 10 to 15 minutes. Give the tiles a light scrubbing with an all-purpose scrubber sponge, rinse and towel dry.
Fill a spray bottle with distilled white vinegar, and spray the blue stains on your tile. Allow the vinegar to set for 10 to 15 minutes. Pour a tsp. of salt on an all-purpose scrubber sponge, and lightly scrub the tile, combining the salt and vinegar. Rinse the salt and vinegar from the tile with clear water, and dry the tile with a towel.
Mix up a baking soda and water paste to remove blue stains on tile. Pour ½ cup of baking soda in a small bowl, and mix in just enough water to form a paste. Hose the tile down with your shower hose, and apply the baking soda paste to the tile with a scrubber sponge. Use circular motions to remove the blue stains. Rinse the tile again to remove the baking soda, and dry the tile with a towel.
Spray an oxygen bleach product on the tile, and allow it to sit for approximately 15 minutes. Wet a sponge and wipe down the tile to remove the blue. Give the tile a rinse to remove the oxygen bleach residue, and dry the tile with a towel.
Rinse the tile with your shower hose. Wipe the wet tile down with a melamine foam sponge. The melamine foam should remove the blue copper stains easily and with very little pressure applied. Give the tile a second rinse, and dry it with a towel.