Black deposits in low flow toilets

Discussion in 'Toilet Forum discussions' started by Bonnie, Dec 13, 2004.

  1. Bonnie

    Bonnie New Member

    Messages:
    7
    This question was asked in July 2001 by another woman but got no responses. Now, I am having the identical problem. She wrote, "Has anyone else experienced a problem with nasty black deposits at the waterline in the bowl of a low flow toilet? Ever since my apartment bldg replaced our old toilets with the low flows, I've had these black deposits appearing almost daily. I thought they were mildew stains, but mildew removers like X-14 have no effect. They come off easily with scrubbing, but I've found no way to keep them from coming back. What causes them? What can I do to prevent them? " In my case, I recently purchased a new house and all three toilets develop these nasty black streaks. They wash off easily but are really disgusting. Is it the pipes, or is it the toilets?
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,129
    Location:
    New England
    This is just a guess...do you use one of those cleaner tablets or other dispenser devices that sits in the tank? the black could be rubber deposits that are being eaten up by the excess chlorine from those devices.
  3. Bonnie

    Bonnie New Member

    Messages:
    7
    Reply to jadnashua

    I have never used a product that sits inside the tank. All I use is a pine-scented cleaner and brush. It is a mystery. The streaks that form in the tank come from the small holes underneath the rim. Sometimes the black substance forms a ring at the water line first, then it forms lines down from the holes to the water line. Other times, the streaks will "grow" from under the rim and ultimately reach the water in the bowl. Once the bowl is cleaned it takes approximately 2-3 days for it to start all over again. I have never, ever seen anything like this. I am beginning to regret purchasing this new house with low flow toilets.
  4. ocpilot

    ocpilot New Member

    Messages:
    6
    Is the surface (i.e. the path between the rim holes and the waterline) etched or rough there maybe from mineral deposits? If so it could be allowing small amounts of moisture to stay on there (instead of running down into the water). This would be especially pronounced if you flush that toilet infrequently.

    I had a similar issue previously, however it was a type of mildew/mold and seemed to crop up a certain times of the year (not sure if because of the water or the environmental conditions). In my case, it seemed to accumlate where someone had apparently scratched the bowl serface with a rough brush.

    I ended up replacing the toilet and problem was solved.

    Here is one thing to try to verify it isn't mold/mildew, go ahead and use a "blue" cleaner/dispenser. I'd bet if it is mold, normal flushing will probably eliminate or at least retard.
  5. Bonnie

    Bonnie New Member

    Messages:
    7
    I am willing to try almost any suggestion. The house is only four months old. All of the toilets are new. This problem has been occuring since the day I moved in.
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,129
    Location:
    New England
    I don't think that you can attribute the stains to the toilets, or everyone would see the same thing. My guess is there is something in your water. If you take a glass and fill it with cold water from the tap then let is sit for several days - leave it for up to a week or so. See if you get similar things.

    Maybe someone else will have an idea. Did you say that others in your neighborhood have similar problems? Maybe you should take it up with the city or town water people .
  7. Bonnie

    Bonnie New Member

    Messages:
    7
    I have asked three other neighbors and none seem to have this problem (or they won't admit it.) In the last two days I have had a plumber, then his supervisor, come to the house to investigate. Neither one has seen anything like this before. The supervisor said to try a bleach-type tablet in the tank. His reasoning was that low flow toilets do not eliminate all of the water in the tank with each flush - and that might be promoting a mold/mildew buildup. The second plumber checked the inside of all three toilet tanks and he also went into the attic to see if the water heater had any type of residue in the pan. (To be honest I'm not sure really why he went into the attic or what he looked at...) Everything looked clean. I have decided that low flow toilets are not all that great and I would prefer to have traditional toilets in my home.
  8. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,129
    Location:
    New England
    None of the toilets exchange all of the water with each flush. They do flush all of the water out of the bowl, but there is always a little left in the tank (some more than others).
  9. Gary Slusser

    Gary Slusser That's all folks!

    Bonnie, it's a water or air quality thing and has nothing to do with the toilet type unless there is 'rubber' deteriorating in the tank; again due to water quality. How will you feel after replacing these toilets and still having the problem? Are you on well or city water? City water with chlormines in it is very hard on 'rubber' gaskets and seals. It causes black smears that are hard to get off, so I suspect you have some type of air borne something.

    Gary
    Quality Water Associates
  10. And, like them or not, low flow toilet are now "traditional." Unless you get illegal imports from Canada that still flush with 3.5 gallons, in the U.S. we're stuck with 1.6 gallons (and some newer ones even less).
  11. LonnythePlumber

    LonnythePlumber Plumber, Contractor, Attorney

    Messages:
    319
    Location:
    Wichita, Kansas
    Rubber Dissolving

    I relate these complaints to rubber dissolving somewhere in the system. While you maybe only notice the black marks in the toilet bowls they may also be occuring at other fixtures but because the water does not sit, it is not noticable. I would take Jim's suggestion to let a glass sit.
    I would not think the residue is due to the toilets. More likely it is related to the toilet supply tubes if it is not occurring at other fixtures.
  12. Bonnie

    Bonnie New Member

    Messages:
    7
    I will try jadnashua's suggestion and let water sit in a clean cup for a week to see what happens. I will post the results of my "experiment" next week.
  13. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,129
    Location:
    New England
    Someone else suggested it, but you may have missed it - many people use the flexible hoses to connect their toilets to the shutoff valves. Some of these are better than others. Some places also sell some that are not rated and certified - thus, the quality of them and their components may be suspect. They're only a couple of bucks - you migh want to consider replacing it since the interior of the hose may be the source of the black marks.

    Also, take the top off of the tank, and lift up the flapper valve. See if you have black crud on it. If you do, replace the flapper valve. This rubber may look okay, but be deteriorating. I've seen some that just felt slimy, not from contaminants, but just from decomposing in the water. Rub your fingers over both the top and bottom of the flapper valve. And last, the rubber bushings that go around the bolts thathold the tank to the bowl could be in the same state - i.e., soft and slimey. They may need to be replaced.
  14. Bonnie

    Bonnie New Member

    Messages:
    7
    The customer service department for the house builder has arranged for someone to come to my house tomorrow to test the water in the water heater. I have not spoken to this person directly, but I was told by customer serivce that perhaps there is bacteria in one or both of my water heaters causing gunk to come out the toilets!?! If that is true, then my drinking water must have gunk also! Can water heaters that are only a few months old become contaminated like that? If so, what are the options to correct the situation?
  15. LonnythePlumber

    LonnythePlumber Plumber, Contractor, Attorney

    Messages:
    319
    Location:
    Wichita, Kansas
    Hot to Toilet?

    Water from the heater does not go to your toilets. There is either a major miscommunication or you're talking to the 3 stooges. I cannot believe the service department of your builder includes a licensed plumber.
  16. Terry

    Terry Administrator Staff Member

    Messages:
    15,118
    Location:
    Bothell, Washington
    Black crud

    I notice black crud at the water line in two toilets that I see often.

    One is the American Standard Glenwall and the other is the American Standard Champion.
    Other toilets in the same households but of different brands do not have the black crud.
    Last edited: Dec 8, 2008
  17. dwpecksr

    dwpecksr New Member

    Messages:
    24
    Location:
    Kansas
    black in toilets

    well after reading all these threads I would say that it is the supply tube that supplys the water to the tank. I have that problem in my shop on city water. I used a bif braided water supply tube. It also may be coming from one of the componets in the tank. I suggest useing copper chrome supply tubes.
    :) :)
  18. Deb

    Deb Plumber

    Messages:
    200
    Location:
    Idaho
    Deb

    If someone else told you this already, I missed it. Do NOT (ever) use those clorox cake type tablets in your toilet tank (a plumbing supervisor advised this?) Virtually all toilets come with labels telling you not to use these, the blue liquid stuff or really anything else that goes in the tank.
    What brand is this toilet?
    Deb
    The Pipewench
  19. nancyjfox

    nancyjfox New Member

    Messages:
    1
    I'm having the same problem!

    I have lived in this house for 14 years and never had any problem with my old toilets until I recently replaced all 3 toilets; 2 with toto low flush and 1 with Kohler low flush. Now have these nasty black mildew-like spots that show up every couple of days in all 3 toilet bowls right at the water line. You're right, it's disgusting. Was recently diagnosed with diabetes, and was thinking that maybe the sugar in my urine was causing it...until I read Bonnie's posting. Also my Doctor says he's never heard of that. I scrub my toilets with scouring powder AND with a pumice stick to remove hard water deposits at the water line, so there's nothing that would cause anything to "stick" at the water line. Does anyone know what causes this? Grateful for any advice. Thanks, Nancy
  20. Terry

    Terry Administrator Staff Member

    Messages:
    15,118
    Location:
    Bothell, Washington
    I"m not a fan of pumice or powders.
    They will scrape up the bowl, and give more traction for stuff to hang on.
    I like to use the liquid cleaners that some some sterilizing power. Lysol and Clorox are two I've used.
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