Black Goo in Jetted Tub

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Dear Home Ec 101:
Help! I’ve got funky stuff coming out of my jetted tub. I turned it on the other night and bits of black sludge ruined my bath. How do I clean out the jets? What is it, anyway?
~ Jetty Betty

how to clean jetted tub

Heather says:

Do you really want to know what that sludge is? Each time you bathe and use the jets tiny bits of skin, body oil, dirt, and soap are left in the jets. This moist environment is just perfect for bacterial growth. YUM!

So, here are some steps to clean and maintain your jetted tub.  If you have a septic system consult a professional, as the chlorine bleach may kill off the good bacteria that keeps your system in working order.

For tubs that have not had a deep clean in several months begin with the first step otherwise skip to step number two.

  1. Fill the tub with hot water just high enough to operate the jets, add between 1/2 and 1 cup of dishwasher detergent and run the jets for 10 – 20 minutes.
  2. If it has been a long time since your tub has had a thorough cleaning drain, and repeat with 1 – 2 cups of bleach instead of the dishwasher detergent.
  3. Drain and fill again with plain hot water to rinse out the jets.
bathroom cleaning
Tips to keep your bathroom squeaky clean!

I typically run a bleach cycle every month or two and have never had a problem.

In addition there is a product called Whirlout available.  I have not tested this product and cannot verify its effectiveness.

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10 thoughts on “Black Goo in Jetted Tub”

  1. I read many blogs from the gurus of “home makers” and yet I sometimes don’t see anything but the same easy answers that really don’t solve the problem, but create more problems. Let’s take a clogged drain for an example. The detergent, the same one you suggest above, that you have been using in the kitchen sink has been coating the walls of the pipes for years. Soap is just a natural coating for bio-film. Now Drano will do a job on the pipes, the acid test, and will clean them up good, and in a number of years your metal pipes will have holes in them.

    Bleach is the all around sanitizer but is not really that strong to continually clean a jetted tub because it looses its strength as it cleans, and you really don’t know if it did the job thorough or not. As bleach sanitizes it loses its free available chlorine to chlorimides … one reason that chlorine needs to be added constantly to pools …. it’s constantly cleaning the never ending dirt. Using a lot of bleach in a jetted tub starts to break down the gaskets and any rubber it comes in contact with, making the 30+ feet of piping very vulnerable to leakage causing more problems in your house.

    Bio Cleaners are what I call the “PacMan” of the Jetted Tub pipe cleaners. These good bacteria and/or enzymes scrape the walls of the pipes until they are clean and there is nothing more to clean. Bio cleaners are green and effective and do just as advertised, they clean pipes whether in a jetted tub or a sink. For this concern, they (bio cleaners) clean jetted tubs just fine so that the pipes are bacteria free and human gunk, etc has been scraped off the walls making the spa ready for a relaxing bath.

    I did the research, and you can find out more information about how to clean a jetted tub, spa, whirlpool bath, jacuzzi, etc on my website,


  2. Oh wow! Thank you for this!! When we moved into our house, we turned on the jets only to discover some pinkish stuff that came out. Which I guess is from the hard water buildup. I avoid using our lovely jet tub because of it! I'm going to try this! Thanks again!

  3. When we bought our current house we were advised to use Milton disinfectant – about 10 caps worth in a bath filled with enough cold water to operate the jets without getting splashes every where – regularly like once a month in our bath.

  4. Cleaning your Jetted bath tub:
    1. Fill tub with hot water to a couple inches above jets.
    2. Pour in about a half cup of bleach.
    3. About a 1/4 cup of cascade complete dish washing detergent Granulated is fine in emergencies.
    4. Using a rubber band, take cheese cloth and cover the suction fitting to catch flakes from recirculating.
    5. Run the jets for 15 minutes.
    6. Observe gunk and try not to choke.
    7. Empty tub refill with cold water to above jets
    8. Run jets to rinse – 10 minutes then empty.

    Ask yourself, where does “Fungus” commonly known as mold grow?……. In a dark and damp environment…just like the plumbing on your tub. So…I always add another step.

    9. Fill tub with water to a couple inches above jets and add a cup of apple cider vinegar, circulate 10 minutes then drain. The apple cider contains at least 5 different anti-fungals.
    It’s hard to find but, use “Calgon Take Me Away” in every bath.

  5. The lodging industry uses a product made by Scientific Biofilm Solutions called Oh Yuk. Obviously hotels can’t have black crud come out of the jets while patrons are bathing.

  6. The lodging industry uses a product made by Scientific Biofilm Solutions called Oh Yuk. Obviously hotels can’t have black crud come out of the jets while patrons are bathing.

  7. Hi,
    I have had good success with cleaning our jetted tub monthly with 1 cup liquid bleach and 1/4 cup cascade powder.

    I have been doing this for over 1 year now without any problems……

  8. I found this inexpensive product called Plumb Clean (the one with the yellow label), that when used as directed, has effectively worked in my whirlpool bath. I use it regularly and have had no black yucky flakes or oily residue in my bath! Finally I can take a relaxing bath again and not have to worry about disgusting germs! Awesome! P.S…I wonder why the kitchen and bath manufacturers don’t tell you this…bleach can ruin your plastic seals in your tub and then you have bigger issues.


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