Verdigris in bathtub drain?

May 27, 2010 9:58 AM

How to treat the bright green deposit in my bathtub drain?

While cleaning my bathtub from an unusual angle, I noticed quite a lot of brilliant green beneath the crossbar trap in the drain. I plumbed the drain with a wad of paper towel, which came back smeared with a bright turquoise deposit. Verdigris, I assume - which surprises me, because I'm in a relatively new building and I didn't think any of my plumbing was copper.

Whatever it is, how do I clean out or neutralize the green? This is a matter of a little concern, because despite regular and vigorous plunging my tub remains a slow drainer, and water (probably with a bit of that poison-green stuff dissolved in it) will occasionally back up and wash over my feet during showers.

posted by Iridic to home & garden (10 answers total)

Sounds like Mineral deposits. Try a product like CLR (or one of it's equivalents).
posted by horsemuth at 10:01 AM on May 27, 2010

I doubt those deposits are related to the drain being slow.

Side note: Instead of plunging, have you tried a Zip-It? They're just a few bucks at the hardware store and I bet you'll pull out an absolutely enormous, stinky, disgusting hairball from your tub drain the first time you try it.

Seriously, you should be sitting down and have a barf bag at your side. Maybe have someone there to catch you if you pass out. Ugh. I might lose my lunch just sitting here typing about it.
posted by bcwinters at 10:08 AM on May 27, 2010 [1 favorite]

addressing your second problem (not that you asked)-- is it a tub with a lever to stop the drain (instead of a plug)? If so, take the grate off and go around with a pair of needlenose pliers.

Those types of drains catch hair something wicked, and plunging and drain cleaner don't get the job done. If it's the scenario that I'm thinking of, you will find a massive, disgusting hairball and totally improved sink performance.
posted by Mayor Curley at 10:13 AM on May 27, 2010 [1 favorite]

I had this when I rented a house with a well. Not sure what the deposits were, but CLR cleared up the majority of it. Also the water tasted horrible.
posted by wrnealis at 10:14 AM on May 27, 2010

My mom's bathtubs all have it. It's most likely copper deposits -- do you have well water?

Nth-ing CLR whether you have well water or not; if you have well water that has a lot of copper in it, you might want to call up the Culligan Man and see about getting a filter put in, at least for your drinking water -- you probably don't want to be drinking water with a fuckload of copper in it, even if it doesn't have that sulfur taste from bad well water. My mom's well produces really sweet-tasting, delicious water. We still need the filter though; drinking copper-contaminated water is not very good for you.
posted by kataclysm at 10:36 AM on May 27, 2010

I don't have copper in the immediate vicinity of my drains either, but I have noticed that some combination of showertime products, in close proximity, do sometimes turn that turquoise color in a slow drain.

I second the ZipIt for pulling out anything that might be making the drain slow (which, in my experience, has included the little plastic cover that goes over shaving razors, and a toothpaste cap), and then see if the green goo still happens.
posted by Lyn Never at 12:01 PM on May 27, 2010

>> ... I didn't think any of my plumbing was copper.

The drain body is almost certainly brass, chrome plated on the visible surfaces, maybe not plated on the inside.
posted by Bruce H. at 12:38 PM on May 27, 2010

Instead of plunging, have you tried a Zip-It?

I have, actually, but that built-in crossbar I mentioned makes it impossible to ply a Zip-It. Varying Mayor Curley's tip, I think I'll remove the overflow plate and try snaking one down that way.

It's most likely copper deposits -- do you have well water?

The water comes direct from Lake Michigan, so I suppose it's some chemistry of cleaning products and/or a reaction from brass in the drain. Hopefully CLR will clear it up!
posted by Iridic at 2:25 PM on May 28, 2010

Um, whoa. We have these grainy, bright green grains that shoot out of the bath taps every time we fill the bathtub. I imagine that it is also coming out of our other taps, we just don't notice it because it goes immediately down the drain. We're also in Chicago, on the northside. I'd never heard of verdigris, but now I'm kind of freaking out because we drink and bathe in this water all of the time. What on earth should we be doing about this? Should we avoid drinking our tap water? Bathing in it?
posted by jeanmari at 7:40 PM on May 30, 2010

Hey jeanmari -- you're drinking city water, so the copper probably isn't actually in your water. Somewhere in your building there is, most likely, some older copper, brass, or bronze plumbing/taps/etc., which is shedding verdigris into the water.

The water is almost certainly OK to bathe in, and probably OK to drink as well; you just need to flush the pipes before using the water for drinking or bathing. I believe that the current USDA guidelines are to turn the taps on and keep the water on for 15 seconds after you see the last of the green grains come out of the faucet before collecting the water for drinking or cooking purposes. If you're really concerned about copper levels in your water, I would contact your county Extension and try to find out about getting your water tested, but my suspicion is that it might be more trouble than it's worth.
posted by kataclysm at 9:59 AM on June 1, 2010