Okay, a couple years ago I remodeled my bathroom and purchased an American Standard toilet. Now for my question, I'm constantly getting this black sort of rubbery stuff in the water that is very sticky. This was also true for my previous toilet. Seems the gaskets are degrading??? I don't use anything in the tank as far as cleaning, voids warranty, so what could be causing this? One last question....is there someone who makes an adapter for the larger flush valve to one that is of a more common size?