View Full Version : Black Toilet Bowl Ring - Why?
DALEPQ
02-28-2025, 11:44 AM
Basic Info.: In Fernandina, built 2012, Nova Filter 3 years, new filters with approx. 4000 gals. used.
We were gone about 12 days, returned to find ugly black toilet bowl ring
in main bathroom. Looked to be some kind of "micro" particles only in that
toilet., tank was clear. Surprised that would happen with the Nova filter.
Any idea what would cause this, and is our water safe to consume ??
Bogie Shooter
02-28-2025, 11:48 AM
What did Nova say?
Marathon Man
02-28-2025, 01:08 PM
Google it. Explanations can be found. One cause is a breakdown of the bowl surface allowing bacteria growth.
Pondboy
02-28-2025, 02:31 PM
Probably mold
Topspinmo
02-28-2025, 04:53 PM
So, water softener don’t work? I don’t have softener, I have never had that, even after 2 weeks being gone.
asianthree
02-28-2025, 04:59 PM
So, water softener don’t work? I don’t have softener, I have never had that, even after 2 weeks being gone.
I thought OP said Nova system, no mention of water softener
laryb
02-28-2025, 07:10 PM
I don't have any chlorine smell or taste after installing our Nova system. I'm not a chemist, but I think the lack of chlorine might be allowing bacteria to develop in the untreated standing water.
gorillarick
02-28-2025, 07:42 PM
I know nothing about Nova.
Black ring sounds like a carbon (charcoal) filter collapsed/leaked into the water.
Should look like very fine black particles.
Definitely won't kill you, but I wouldn't make a habit of it.
___
If you suspect mold/bacteria: Add a cup of bleach while still in there. If bacteria, it will seem to disappear.
(oh, and don't forget to flush your toilet before leaving for any length of time)
Altavia
02-28-2025, 08:21 PM
I know nothing about Nova.
Black ring sounds like a carbon filter collapsed/leaked into the water.
Should look like very fine black particles.
Definitely won't kill you, but I wouldn't make a habit of it.
We get it and don't have a water filter.
As others posted, it's a biofilm (mold, bacteria, algae, ???)
Try adding a cup of bleach or vinegar to the water before leaving any length of time.
retiredguy123
02-28-2025, 08:32 PM
The ring at the water level is an accumulation of calcium deposits that is formed when the water in the bowl evaporates. The mold grows on the calcium ring. Use a pumice stone to remove the calcium from the toilet bowl and you will stop the mold from growing.
BookerBo
03-01-2025, 04:40 AM
I have looked into this. It is likely dissolved Manganese (Mn), and a simple water filter cannot take this out. From my understanding the wells in the villages produce varying levels of Manganese. From 0 to over 12 ppm at the source. I am not sure how many wells there are but I think it is somewhere around 5. As the water travels in the pipes and is exposed to air and chlorine some of the Mn precipitates (goes from dissolved to particulate) and the water softener will take out those particles that arrive at your house but not what is still diluted. As the water takes anywhere from 2 to 6 days to reach any individual home different homes will experience different levels. Our well for Hawkins is at 12 ppm and will forever have that amount. (the well is over a million years old and is 1000 ft deep)
I did a simple test of our water and it contained greater than 1.9 ppm which was the most that test could measure. It only takes .5 ppm to cause black rings. you will also find it in the screens of your faucets, sink traps and the dishwasher. The dishwasher can be worse as the PH level is raised from the detergent and this is one cause of Mn "precipitating". The other is exposure to air and chlorine. If you have a charcoal filter, you may develop strong odors in your sinks and dishwasher as the charcoal neutralizes the chlorine allowing the bacteria that “like” manganese to grow. A slimy substance in the tank of your toilet is an indicator of bacteria as well.
There are very expensive filters to remove Mn and is the same filter used to remove iron. They are called air injection filters and use a venturi to suck in and maintain an air pocket at the top of filter. This causes the Mn to precipitate and fall to the filter to bed to be backwashed out later. The units I have looked at can only remove upto 2 ppm of dissolved Mn and cost between 700 to 1000 or more. Personally, I wont buy a filter until I have my water professionally tested for a period of 30 days. Wouldn’t want to buy a 2 ppm filter when the water coming in has 4 ppm.
loufromnewjersey
03-01-2025, 05:25 AM
Nothing to do with the filters. This is mold from standing water. Clean bowl before you go and/or put some bleach in.
Cuervo
03-01-2025, 06:56 AM
I don't have the problem but was curious, the links below are from YouTube. It seems vinegar could be the solution.
https://www.youtube.com/watch?v=tg9tnNG4J18&ab_channel=PapaJoeknows
https://www.youtube.com/watch?v=KsMp4rx3E8k&ab_channel=JMGENTERPRISES
https://www.youtube.com/watch?v=TrMdyD_Uh4k&ab_channel=CleaningHowTo
crash
03-01-2025, 07:41 AM
Basic Info.: In Fernandina, built 2012, Nova Filter 3 years, new filters with approx. 4000 gals. used.
We were gone about 12 days, returned to find ugly black toilet bowl ring
in main bathroom. Looked to be some kind of "micro" particles only in that
toilet., tank was clear. Surprised that would happen with the Nova filter.
Any idea what would cause this, and is our water safe to consume ??
It is a mold you will see it on any hardscape you have in your yard also. The Nova filter has a carbon filter as one of the filters this removes the chlorine from the water. The water in the bowl will grow this mold if left unflushed for a period of time. You can add to your bowl something that adds chlorine when you flush to help with this but will still grow if left unflushed for an extended period.
jimkerr
03-01-2025, 08:27 AM
The ring at the water level is an accumulation of calcium deposits that is formed when the water in the bowl evaporates. The mold grows on the calcium ring. Use a pumice stone to remove the calcium from the toilet bowl and you will stop the mold from growing.
This is the correct answer! I’ve done this on one toilet of ours that doesn’t get used a lot and gets a black ring. The pumice stone takes care of that ring and it stops it from coming back for quite a while.
MollyJo
03-01-2025, 08:41 AM
I would not leave bleach in the toilet bowl, it could erode the surface permanently.
rrman77
03-01-2025, 08:54 AM
You are right!!!
rrman77
03-01-2025, 08:55 AM
No chlorine left in water, so long standing water can allow mold to grow. Drop in a capful of bleach before you leave.
Jhind
03-01-2025, 09:08 AM
The Palmerstone will scratch the porcelain surface, allowing more mineral buildup in the near future. You are opening up the porosity of that surface to more issues.
Toilets are made, and finished with a smooth porcelain finish for a reason, to move the waste materials with very little friction
Boiler
03-01-2025, 09:08 AM
We were told by Nova installer that system takes chlorine out of water. To replace the chlorine to continue sanitation, we bought chlorine discs from Lowe’s and put in the toilet tanks. It works like a charm.
The Palmerstone will scratch the porcelain surface, allowing more mineral buildup in the near future. You are opening up the porosity of that surface to more issues.
Toilets are made, and finished with a smooth porcelain finish for a reason, to move the waste materials with very little friction
I agree. Don't scour porcelain.
Skip
retiredguy123
03-01-2025, 09:38 AM
I agree. Don't scour porcelain.
Skip
I have used a pumice stone to remove calcium/lime deposits from toilet bowls for many years. That is what it is recommended to do. You need to keep the stone wet while using it. I have not found any cleaning chemical that will remove the calcium build up. Bleach and vinegar definitely do not work.
Can you scratch a porcelain toilet bowl with a pumice stone? Yes, if you use it incorrectly.
GladysM2024
03-01-2025, 10:05 AM
It is a bacteria and you need to chlorinate the entire toilet.
If you are not regularly flushing, bacteria grows even with a filter.
Flush your hot water heater of sediment and it will be ok to use the water.
GladysM2024
03-01-2025, 10:07 AM
If that were the case it would be in all toilets, bowls, faucets.
Nova Filtration
03-01-2025, 10:19 AM
I know nothing about Nova.
Black ring sounds like a carbon (charcoal) filter collapsed/leaked into the water.
Should look like very fine black particles.
Our filters are made solid, they can't collapse, the ones that collapse are call pleated filters
The ring at the water level is an accumulation of calcium deposits that is formed when the water in the bowl evaporates. The mold grows on the calcium ring. Use a pumice stone to remove the calcium from the toilet bowl and you will stop the mold from growing.
We don't recommend use a stone it can scrach the surface making the issue worse
Nothing to do with the filters. This is mold from standing water. Clean bowl before you go and/or put some bleach in.
Worth a try
This is the correct answer! I’ve done this on one toilet of ours that doesn’t get used a lot and gets a black ring. The pumice stone takes care of that ring and it stops it from coming back for quite a while.
Not recommended
I would not leave bleach in the toilet bowl, it could erode the surface permanently.
Not true, if you think about all the homes in the USA that don't have filters the chlorine is there all the time.
The Palmerstone will scratch the porcelain surface, allowing more mineral buildup in the near future. You are opening up the porosity of that surface to more issues.
I agree don't use it
Toilets are made, and finished with a smooth porcelain finish for a reason, to move the waste materials with very little friction
I agree. Don't scour porcelain.
Skip
Correct
Nova carbon does a great job removing Chlorine and chemicals.
The lack of it in toilets causes this.
We recommend a good scrubbing with CLR in case there is a calcium deposit since the home does have a softener.
or
For hard water stains or particularly stubborn marks, sprinkle baking soda onto the affected area, then pour vinegar on top to create a fizzing reaction.
Then a chlorine tablet to the tank, (no it will not harm anything)
Then about 2X a year use Clorox Clinging Bleach Gel under the rim, it has a angled tip to get under the rim.
retiredguy123
03-01-2025, 11:09 AM
If you go to Amazon.com and type in pumice stone, you will get 2000 responses, most of which are sold to clean toilet bowls. None of the chemicals suggested on this thread will remove a calcium ring around the toilet bowl water line. I have tried them all.
CybrSage
03-01-2025, 11:12 AM
I have used a pumice stone to remove calcium/lime deposits from toilet bowls for many years. That is what it is recommended to do. You need to keep the stone wet while using it. I have not found any cleaning chemical that will remove the calcium build up. Bleach and vinegar definitely do not work.
Ever try CLR? It is designed to remove Calcium, Lime, and Rust deposits.
I do not get black ring issues so I have not tried it. Heard good things about CLR though.
Risuli
03-01-2025, 11:14 AM
Be careful about the chlorine disks that drop in the tank. Yes, they will keep mold from forming, but depending on the type of toilet they can cause issues. We have Champion 4 toilets and the "drop in" chlorine tablets erode the seals on the flush valve which will cause a continual slow leak.
CybrSage
03-01-2025, 11:17 AM
Then a chlorine tablet to the tank, (no it will not harm anything)
I looked at over 10 different plumbing company websites about chlorine tablets in the toilet tank and they all agreed it is bad to do. The chlorine destroys the rubber gaskets and plastic parts. Some said it also causes metals to rust faster.
This is because the tablets greatly increased the amount of chlorine in the tank from 5mg/L to 1000mg/L.
"Chlorine tablets can damage toilets by corroding and breaking down plastic and rubber parts. This can lead to leaks, clogs, and other issues. "
retiredguy123
03-01-2025, 11:19 AM
Ever try CLR? It is designed to remove Calcium, Lime, and Rust deposits.
I do not get black ring issues so I have not tried it. Heard good things about CLR though.
Yes, I currently have two bottles of it and also Lime Away. These products are good for cleaning chrome drain popups and fixtures, but they cannot remove a calcium ring from a toilet bowl. I guess, if you want to clean your toilet bowl every day, you can avoid calcium build up, but most people don't want to do that.
Nova Filtration
03-01-2025, 11:20 AM
Be careful about the chlorine disks that drop in the tank. Yes, they will keep mold from forming, but depending on the type of toilet they can cause issues. We have Champion 4 toilets and the "drop in" chlorine tablets erode the seals on the flush valve which will cause a continual slow leak.
We disagree, have hundreds of customers using them, including myself for 13 years.
If that were the case wouldn't any home without a filter meaning there's chlorine in their toilets have a seal issue?
Nova Filtration
03-01-2025, 11:24 AM
Yes, I currently have two bottles of it and also Lime Away. These products are good for cleaning chrome drain popups and fixtures, but they cannot remove a calcium ring from a toilet bowl. I guess, if you want to clean your toilet bowl every day, you can avoid calcium build up, but most people don't want to do that.
Perhaps because your diluting it with water that's already in the bowel.
Empty most of the water fill it with 100% Lime away or CLR it will absolutely remove calcium
But it has soak for several hours.
THis stuff will dissolve a seashell
retiredguy123
03-01-2025, 11:39 AM
Perhaps because your diluting it with water that's already in the bowel.
Empty most of the water fill it with 100% Lime away or CLR it will absolutely remove calcium
But it has soak for several hours.
THis stuff will dissolve a seashell
I have even tried emptying the bowl and soaking the bowl with an entire container of CLR overnight. It didn't work. But, gently rubbing a wet pumice stone on the bowl surface will remove the calcium build up in a few minutes. If you are afraid of scratching the bowl, then don't use it, but it works for me.
Bwanajim
03-01-2025, 01:01 PM
I lived in South Florida my whole life and never had this issue. I don't have any kind of water filter softer system. But if the toilet's not flushed every day or two I get that black ring and I don't understand what the hell it is!! I have to remember to go on any other two bathrooms to flush them.
DonnaNi4os
03-01-2025, 02:40 PM
My best guess would be mold, esp if you kept the lid closed. Pour some bleach on it and that should eliminate it if it should be mold.
RICH1
03-01-2025, 03:35 PM
maybe just maybe it's the black bladder failure, in your expansion tank.. 60.00 bucks common fail
Nova Filtration
03-01-2025, 04:20 PM
maybe just maybe it's the black bladder failure, in your expansion tank.. 60.00 bucks common fail
Rich, I agree but since this is cold water line not hot I doubt it.
But they fail all the time we see several a week that need replacing
they only last on average 3-5 years, good idea to check the bladder with a tire gauge they should be about 5-60 psi every 4-6 months
When they fail the water pressure increases in the entire house
EdFNJ
03-01-2025, 05:42 PM
.
Seeing your posts just reminded me it’s time to replace my filters. :D :ho::D
Rodneysblue
03-01-2025, 09:57 PM
Basic Info.: In Fernandina, built 2012, Nova Filter 3 years, new filters with approx. 4000 gals. used.
We were gone about 12 days, returned to find ugly black toilet bowl ring
in main bathroom. Looked to be some kind of "micro" particles only in that
toilet., tank was clear. Surprised that would happen with the Nova filter.
Any idea what would cause this, and is our water safe to consume ??
Maybe not flushed completely, leaving some material behind.
crash
03-02-2025, 07:13 AM
We were told by Nova installer that system takes chlorine out of water. To replace the chlorine to continue sanitation, we bought chlorine discs from Lowe’s and put in the toilet tanks. It works like a charm.
Not advised to put chlorine in the tank it corrodes the rubber parts and you will be changing out the parts. You want something that goes in the bowl.
retiredguy123
03-02-2025, 07:17 AM
Not advised to put chlorine in the tank it corrodes the rubber parts and you will be changing out the parts. You want something that goes in the bowl.
I agree, but apparently there is a product that claims to be safe to add to the tank water.
crash
03-02-2025, 07:21 AM
We disagree, have hundreds of customers using them, including myself for 13 years.
If that were the case wouldn't any home without a filter meaning there's chlorine in their toilets have a seal issue?
It is not just the chlorine but the concentration. Thinking water from the tap is 2 ppm and a tablet dissolving in the tank can be 1000 ppm depending how long it sits there.
derkster
03-02-2025, 08:54 AM
Yes, the pumice stone is the only thing that works once the ring has formed. I tried vinegar, hydrogen peroxide, and lots of scrubbing but nothing worked until I bought a pumice stone from Amazon. Worked wonders.
Carlsondm
03-02-2025, 09:08 AM
I would not leave bleach in the toilet bowl, it could erode the surface permanently.
I agree. Our builder warned us about this.
Nova Filtration
03-02-2025, 09:32 AM
Not advised to put chlorine in the tank it corrodes the rubber parts and you will be changing out the parts. You want something that goes in the bowl.
I agree. Our builder warned us about this.
We have been recommending the tabs of chlorine for over 13 years, works great.
Over 20,000 homes
No one ever had a problem with the rubber breaking down.
If you're concerned the rubber caskets are about $10 and need replacing 3-5 years or so..
SusanStCatherine
03-02-2025, 10:52 AM
The Kohler toilets we got in 2021 are bottom of the line. They do not have a strong flush and therefore can leave some waste behind in the bowl which is not good for keeping it clean.
We have a Nova whole house filter and also their water softener and we get the black stuff even though our toilets are frequently used and cleaned.
I have used the pumice stone and it works great for removing rings.
There are toilet bowl products where the bleach sits in a container inside the tank and some is released with each flush, so I believe that would avoid damaging inside the tank. Kohler makes self cleaning toilets where the flush is stronger and it has an enclosed area in the tank to put in a cleaner - that's our next step eventually. It's also smooth on the outside base making it easier to clean there as well.
CFrance
03-02-2025, 11:02 AM
We have been recommending the tabs of chlorine for over 13 years, works great.
Over 20,000 homes
No one ever had a problem with the rubber breaking down.
If you're concerned the rubber caskets are about $10 and need replacing 3-5 years or so..
What is the brand name of the tabs that do not corrode the seal in the tank? In 2012, we used 2000 flushes in our new TV house, which we had been using since the 1980s in four different houses--PA, NJ, MI well, MI city). In less than a year, the seals had corroded and leaked. Can't use 2000 flushes anymore.
I'd be very interested to know a brand that does not corrode the seal.
Risuli
03-02-2025, 11:04 AM
We have been recommending the tabs of chlorine for over 13 years, works great.
Over 20,000 homes
No one ever had a problem with the rubber breaking down.
If you're concerned the rubber caskets are about $10 and need replacing 3-5 years or so..
As I mentioned in my prior post, it may depend on the type of toilet. I HAD used the chlorine drop in discs for years in our prior home that had toilets with the "old style" rubber flappers with no issues.
In our current home we have the Champion 4 toilets that use a different flush mechanism that has a round rubber (or plastic/nylon?) ring seal fixed by a hard plastic cap that sits over the water discharge. In our new home I used the chlorine discs for a year and every month or two the toilets would develop a slow leak and I would have to change out the ring seals to get them to stop, only to have the leak reappear a month or two later. After reading up on the issue I found the info about NOT using chlorine in the water tank due to the effect on the seals. I stopped using the discs and since have NOT had the slow leak issue. But I guess your mileage may vary...
ithos
03-02-2025, 11:44 AM
I have used a pumice stone to remove calcium/lime deposits from toilet bowls for many years. That is what it is recommended to do. You need to keep the stone wet while using it. I have not found any cleaning chemical that will remove the calcium build up. Bleach and vinegar definitely do not work.
Can you scratch a porcelain toilet bowl with a pumice stone? Yes, if you use it incorrectly.
This seems to be a very long thread for something so basic. Toilet rings can occur(edit) anywhere you live regardless of your utility provider.
It only takes a few seconds to get rid of the black ring that forms at the waterline. Simply use Lysol Power Toilet Bown Cleaner. It has Hydrochloric acid.
If there is reason not to use it then please respond.
I do agree that the pumice sticks work very well but just take a little longer. Maybe difficult for folks with arthritis.
rjrobart
03-02-2025, 04:01 PM
You need a better whole house filter system.. I'm talking at least a $2000 plus. A system you can actually feel comfortable drinking your faucet water. That eliminates all minerals coming into your home. Cheaper systems just don't get the job done. And of course add a water softener to it. The best, healthiest, and why is this investment you can make on your home. Bar none!
I put in a Rain Soft top of the line system in, and I don't buy bottled water anymore. There is no doubt I have the purest, softest water in all the villages. Open your wallet and do what's right for your family.
Philipd411
03-02-2025, 07:58 PM
Basic Info.: In Fernandina, built 2012, Nova Filter 3 years, new filters with approx. 4000 gals. used.
We were gone about 12 days, returned to find ugly black toilet bowl ring
in main bathroom. Looked to be some kind of "micro" particles only in that
toilet., tank was clear. Surprised that would happen with the Nova filter.
Any idea what would cause this, and is our water safe to consume ??
Does a diabetic use this toilet? I am a diabetic and use the guest toilet and it gets this ring. My wife uses the master bathroom toilet and it does not get the same ring.
Bwanajim
03-03-2025, 09:09 PM
Basic Info.: In Fernandina, built 2012, Nova Filter 3 years, new filters with approx. 4000 gals. used.
We were gone about 12 days, returned to find ugly black toilet bowl ring
in main bathroom. Looked to be some kind of "micro" particles only in that
toilet., tank was clear. Surprised that would happen with the Nova filter.
Any idea what would cause this, and is our water safe to consume ??
I lived my whole life in Fort Lauderdale and never had these rings and had no filter system. Here it seems like it. The toilet isn't flushed every day there's a ring and I don't know what the heck it is.
CarlR33
03-03-2025, 10:41 PM
This product may help?
https://youtu.be/lzXt-QB8Vzs?si=iiLk4hIAJ1y4RdbU
VAtoFLA
03-04-2025, 04:19 AM
As I mentioned in my prior post, it may depend on the type of toilet. I HAD used the chlorine drop in discs for years in our prior home that had toilets with the "old style" rubber flappers with no issues.
In our current home we have the Champion 4 toilets that use a different flush mechanism that has a round rubber (or plastic/nylon?) ring seal fixed by a hard plastic cap that sits over the water discharge. In our new home I used the chlorine discs for a year and every month or two the toilets would develop a slow leak and I would have to change out the ring seals to get them to stop, only to have the leak reappear a month or two later. After reading up on the issue I found the info about NOT using chlorine in the water tank due to the effect on the seals. I stopped using the discs and since have NOT had the slow leak issue. But I guess your mileage may vary...
@Risuli speaks truth. No problem using chlorine discs in normal flapper toilets, don't use them in your Champion 4 (best toilet in the world IMO). It is the ring seal that will wear in that unit prematurely. I speak from experience and a past love of the chlorine disc replaced by a greater love of the Champion 4 flush.
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