Mark Philben -- Globe Correspondent

Q. During the pandemic, we did a refresh of our half bath by installing new tile and a new pedestal sink. Not even one year later, the sink started to discolor near the drain. The old one had the same problem; that’s why we replaced it. Why does the sink discolor yet the toilet does not? The sink was purchased from a big-box store, while the toilet, made by a different manufacturer, was purchased from a plumbing supply store. Does that matter? We’ve had no issues with discoloration in our other bathroom sinks, tubs, or toilets. We have well water which is hard; however, we have a water filtration and softener system. I’ve tried typical bathroom products, as well as vinegar and baking soda, and nothing will remove these stains. The sink looks dirty. What can be done?

A. This sounds like a problem with the supply lines leading to the faucet. It seems that the water in your house is free of iron when it exits the filter, but then it has to run through a labyrinth of potentially old and new pipes to get to the various fixtures. Since it stained the old sink and nothing else, and now the replacement sink is stained and still nothing else is showing damage, the culprit could be the connection to that sink. Try having the water tested from the bath faucet and compare that with the water tested from another fixture. That could help isolate the cause of the problem.

Q. A few months ago while cleaning our double-glass doors from the inside, one shattered into thousands of pieces the size of a pinky fingernail. I was fully dressed, including socks and a head covering, so only my hands were cut (five small slices). I was terrified and really shaken for several hours.

I contacted the manufacturer. The customer representative focused on replacing the doors. No, thank you; we are using a shower curtain now. She did not answer my safety concerns. I have not pursued this because we did not have a professional install them, rather a builder who was recommended by our reputable plumber.

I am very concerned about this major flaw, which could have injured us or our grandchildren had one of us been showering at the time. Car windshields and patio sliders have been redesigned because of injuries and fatalities from shattered glass. Why not shower doors?

M.M., Portsmouth, N.H.

A. The shower door that shattered is in fact safety glass; all shower doors are tempered glass. The fact that it broke into thousands of smaller pieces and not large shards confirms that. Why it broke when you were cleaning it is a good question. It typically takes a power tool or a sharp rap with a hammer or something to break tempered glass. The glass may have had a flaw.

I would not hesitate to install another tempered glass door. We have never had one break like that. I understand your reluctance, however. A shower curtain is a viable option and less maintenance, too.

Mark Philben is the project development manager at Charlie Allen Renovations in Cambridge. Send your questions to [email protected] . Questions are subject to editing. Subscribe to the Globe’s free real estate newsletter — our weekly digest on buying, selling, and design — at pages.email.bostonglobe.com/AddressSignUp. Follow us on Twitter @GlobeHomes and Boston.com on Facebook.