How to Remove Green Water Stains From Bathtubs

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Things You'll Need

  • White vinegar

  • Sponge

  • Cleaning cloth

  • Lemon juice

  • Soap

  • Ammonia

  • Phosphoric acid

  • Oxalic acid

  • Hydrochloric acid

  • Sulfuric acid


Use acids with care. They are highly toxic and cause skin, eye and lung irritation. Wear rubber gloves and eye protection. Check with your local sanitation department to find out how to dispose of acids properly. Over time, acidic water can cause pinhole leaks in your plumbing. Installing an acid neutralizer to treat all of the water coming into your house could help slow down or even stop the corrosion.

corroded metal drain
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Green or greenish-blue stains on your tubs, sinks, toilets and plumbing fixtures are not only unsightly, but they also indicate a problem that could be very expensive to repair in the long run. If you have acidic water (a pH of less than 7.0), your copper and brass pipes and plumbing fixtures are corroding. The green and greenish-blue stains you see in the bathtub are the result: dissolved copper and brass in your water caused the stains. To remove stains caused by acidic water, use an acidic cleaner.


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Step 1

woman cleaning sink metal
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Pour some plain white vinegar on a sponge or cloth, apply it to the stain, then scrub. Vinegar is 5 percent acetic acid. White vinegar might also remove the green stain from your plumbing fixtures. Lemon juice is also an acid; in this case, citric acid. Use it the same way you would use vinegar.


Step 2

flushing cleaner down drain
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Use a mixture of soap suds and ammonia if mild acids do not remove the stain. Apply the mixture, scrub and rinse. A mixture of half water and half ammonia could also work. Flush your drains with water after using ammonia cleaners.


Step 3

flushing out a drain
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Use phosphoric acid or oxalic acid on stubborn stains. Dilute the acid by mixing 1 part acid with 10 parts water, and use as you would the cleaners described above. Flush out your drains and pipes with plain water. Many commercial cleaning products also contain these acids.


Step 4

diluting acids and flushing bathtub drain
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Use hydrochloric and sulfuric acids, again diluting them and flushing out the pipes after cleaning the stains. You can buy commercial cleaning products that contain these acids.