Do you use chlorine tablets in your toilet tank (or other "blue" tablets to keep the toilet clean)?

Some of those tablets are too hard on and degrade the rubber giving black sludge/disintegrating rubber. Does it seem like that?

Thanks kirkhall for your comment. No, I don't use clorine tank tabs, in fact use chlorine even diluted less and less in bathrooms due to corrosion issues.

But, the plumber did return and said it was the flapper which is deteriorating, causing the black on it's reverse side. So tomorrow a new one will be installed.

Wouldn't you know it, today the same bathroom faucets started leaking. Think we're going to replace that old cabinet, sink, corian ct and faucets and freshen things up.

Home drain/sewage pipes are commonly coated with a black slimey sludge that resembles grease. It's bacteria/bio-slime, call it what you want. It sounds like you may have it in your toilet tank, which seems odd but I'm not a plumber. I'm surprised your plumber didn't mention it as a possibility.

Try cleaning the affected area with a diluted chlorine solution (maybe 4 water to 1 chlorine) plus some dishwashing detergent. Scrub the affected area and let it stay on for 15-20 minutes before rinsing off. Wear rubber gloves. See if that helps.

There are also some commercial products that can be used to clean off the slime but the bleach/water/soap combo often works.

Oh my, that does not sound nice. It didn't have any odor or particulate matter; it was like black oil.

Well, the deteriorated gasket was replaced today (proper fit thing). But I will investigate this bio-slime-hmm.

Well I checked up on the new gasket today and no evidence of black liquid or other on it's underside. Think I'll do that for a few days in a row. When scrubbing out the black marks left from the oily mess in the tank and the bowl, I resorted to bleach as they were so dark and it took quite a while and a lot of muscle power to get them off. I don't think this is Bioslime, as I'd expect such to come off much easier with active scrubbing since it's organic. But, I thank you for your knowledge and will add that to watch for.

Treated water does that. Our water in Arlington VA & Washington, DC is "chloraminated" (as opposed to chlorinated), which degrades them more quickly.

You can live with it and eventually replace, or, if you're lucky, you might find one rated for chloramined water (not too many out there, though). More important is to make sure the flapper fits your toilet. They are not as "universal" as the packages would have you believe. .

This post was edited by homebound on Sun, Jun 9, 13 at 15:29

Thanks homebound. I had no idea of "chloraminated". Yes, the flapper contraption is an old set up-don't no really how to describe, kinda 90 degrees white thing with a plastic arm connector to which the gasket hooks in. Turns out you have to buy just the right arm length to get the right fit. Crazy.

Thanks for the education on this matter. I appreciate it much.