Seeing pink

I had big plans for the holiday weekend. I decided I was going to do a deep clean on the bathroom and seal the marble and grout in the shower area. In the past, a quick scrub of the grout with a magic eraser was sufficient cleaning. The strange, pink spots that show up on the grout usually go away, but I was worried that the eraser was just getting rid of something that was possibly deeper.

The pink spots are caused by serratia marcescens. From wikipedia:

Due to its ubiquitous presence in the environment, and its preference for damp conditions, S. marcescens is commonly found growing in bathrooms (especially on tile grout, shower corners, toilet water line, and basin), where it manifests as a pink discoloration and slimy film feeding off phosphorus-containing materials or fatty substances such as soap and shampoo residue. Once established, complete eradication of the organism is often difficult, but can be accomplished by application of a bleach-based disinfectant. Rinsing and drying surfaces after use can also prevent the establishment of the bacteria by removing its food source and making the environment less hospitable.

Okay, that's great...but I squeegee after every shower and only use liquid soaps to combat soap scum (I've had no soap scum since I got rid of bar soap). I guess there still something sticking around to feed the pink stuff.

There's no way I'm sealing the tile and grout while this stuff is still around. I went to the web to search for solutions. The bleach recommendation would work for anyone with ceramic tile, but with natural stone, an alternative was needed. Enter Bill Vincent, a tile guru for many on the web. He posts regularly on a number of forums and recommends using oxiclean on the serratia marcescens when it's appearing near natural stone.

So I pulled out the tub of oxiclean from the laundry closet and started mixing. I was a little startled that the mixture immediately got hot but I figured that was the oxygen its thing. I slathered the paste on the grout lines with a plastic knife (not easy!!) and waited an hour before scrubbing it off. Then I did the entire routine over again.

Late last night, I used the last of the stone cleaner I have to wash the entire shower area, too. The pink stuff is gone in some areas, but not in all. I'm not sure if I should try another round with the paste today or head out to the store and find a stone safe cleaner that is anti-bacterial. I don't even know if such a thing exists.

Has anyone seen these pink spots before? If you have marble or natural stone, what was your strategy to get rid of them?


  1. I sometimes use the Chlorox bleach pen for the grout lines. It is thick enough to stay in place and doesn't drip (shake the pen before use). Also I use X-14 mildwew spray on the marble tile. I know it says not to, but the installer said he used it on his marble without ill effects. If you have a leftover piece, you can try out different products to make sure the product won't impact your (beautiful) tile. Happy cleaning.

  2. white vinegar should kill both bacteria and fungus, although I am not sure which one that is, I didn't google. . . unless there's an issue with vinegar and oxiclean reacting or vinegar reacting with the stone.

  3. oh I see it's bacteria. rubbing alcohol would work too, but it might dry out your grout and damage. . .

  4. I've used the Oxyclean and it's worked for me. Maybe try it one more time?
    I was also going to suggest the Chlorox Bleach Pen like Eileen did. You could make sure it was just on the grout so it wouldn't etch your marble.
    After it's all clean there is a shower and tile spray from Method that I use everyday to spray down my shower (it's Silver Travertine). I haven't had an issue with the pink stuff since.

  5. Sounds cheesy, but the Sonic Scrubber (as seen on tv) from Bed Bath and Beyond works like a charm to whirl away the yucky stuff! Also, that Shaklee Scour Off works well on grout.

  6. Ok, you're going to laugh, but try using a can of orange Tang (yes the drink stuff) powder. Just scrub it on with your hand with a little tiny bit of water to make it a paste. Let it sit a while then spray it off with water.

    When we lived in the very wet Northwest, our new dishwasher developed this type of yuck on the inside and nothing would clean if off. A Navy guy who lived on submarines while on duty told us to throw a can of orange tang in the empty dishwasher and run it. It cleared it out completely and never came back. Apparently the submarines have a lot of problems with this slime and they carry crates of Tang to combat it.

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