So, I thought to clean the basement bathroom porcelain today and noticed that the sink seemed to drain kind of slowly (uh-oh). Considering that the sink's drain pipe runs shorter and closer to the drain (about a 3 inch drop then a horizontal stretch of pipe) than a regular sink drain (which usually has a 2 foot drop before the u-joint), I pulled the stopper out of the sink. I saw that thick black murky stuff covering a few of the six openings in the drain and under the stopper, it's like the black stuff became a rubber ring of a kind. Once I scoured the stuff off and down the drain, the sink drained better.

Just sharing a "heads-up" alert if you have Ikea sinks in the basement-not only is the moisture level higher downstairs, but the sink's plumbing set-up may also contribute to murky things setting up shop in the drains.

I need to add this detail to my "home manual" pages of how to handle regular maintenance issues.