I have the black stuff too, but...
Our tub has had this problem for over a year now. It only comes out of the hot water tap and once out of the shower head. The only thing different is that we don't have a regular water heater, we have a tankless heater, or an "on-demand" system. I don't know if that makes a difference in what is possibly causing the problem.
Also, and I don't know if this is related but our hot water tap for that tub has always had poor water pressure. The cold is fine and all of the other faucets and the other shower has great pressure but the tub has slow pressure only on the hot water.
Black Spots in Bathtub - Possible solutions
Same problem here. I have a 2 year old home with a water softener and hot water heater expansion tank. I would like to know if everyone involved have either of these additional items.
I contacted my builder's plumbing company and they told me that the black particles are dead bacteria in the hot water heater. The cause is due to the hot water heater being set to high (would like to know for those affected if their setting is above the med temp (B) or not. Solution was to drain/flush the tank for 10 mins and set the temp gauge between (A) and (B). (I did but still see particles sometime - not sure if I flushed the tank well enough).
My gut is telling me that it has to something to do with the expansion tank. For awhile, my water softener was set at a higher than normal setting and I believe that this may have damaged the expansion tank. I will do the tap test (as someone suggested) this evening and see if it sounds like the tank is full of water (if so, the tank is bad) and I will replace.
Lastly, the best solution to remove the black marks from you tubs is from the automotive section at your Wal-Mart or car parts store. Look for Bug and Tar removal/cleaner. It comes in aerosol and spray. It really cleans up the mess and doesn't appear to harm the fiberglass finish.
I hope this help and if anyone resolves the problem, pls let us all know.
Plumber says black spots are broken up washer
he asked me to run the water from the tap for 10 minutes and see. it workd so far only 1 black spot instead of hundreds. i dont want to have to do this every time, however. the faucet is a big one and runs a lot of water. and this seems to happen if you dont use the tub for about 2 weeks. i travel, so when i am out of town it doesnt get used.
Black Specks that wil not go away
I too have same problem and just ran across this site....I've read all the posts, and still appears that there is not a permanent solution. These little black dots/specks are extremely hard to remove from fiberglass tub & surround. I've used bleach (although hesitant too since have septic system) and other cleaning supplies but still will not remove unless I actually use my fingernail and "pick" / scrub them off.
These only appear in the bath in the basement. The house is 10 years old and the water heater is only a few years old now. No rubber gaskets anywhere in plumbing that I know of (except for O-ring to seal water filter and that is brand new).
I certainly think that it is a micro-organism of some sort as others have suggested, but am stymied as to why no cleaning solution, esp. bleach does not even "touch" these things.
Many of these are on the shelf of the surround where what does not hit so do not think it is coming from water heater or the water itself. Also, the hot water, as well as cold, appears crystal clear in a glass.
This almost looks like black over-spray from an aerosol paint can, if that helps.
Thank you for all your help.
Same "greasy" black spots -Gone (maybe for good??)
After reading these posts & talking to AO Smith water heater support the only
source of rubber in my copper H20 supply is the plex connectors. AO Smith said the Anode usually causes "smelly" water.
I replaced the plex connectors with flex copper connectors and no more specks in the hot water to the washer or the bathtub. I will give this at least several weeks before declaring a solution but all is ok after getting rid of the plex which was in sorry shape on the interior.
The specks,flecks I had were black floating which would smear on the porcelain
very difficult to cleanup. So far several hot water tests in the bathtub & washer
with not repeat of the problem.
What are Plex Connectors?
My question is in response to the post by "pd". What is a Plex Connector? I've done some searching on google and not coming up with anything. Are you referring to the flexible water supply hose?
By the way, I am so surprised to hear so many people with new houses complaining of this problem. I have an old Craftsman, 1914, and have been thinking that it is the old pipes. But, over the past five years a number of remodeling projects have happened, except there hasn't been any new plumbing installed, just new fixtures with a little bit of copper piping attached to the old galvanized pipes.