Help us not die of green gunk poisoning.

November 21, 2012 11:11 AM

Is this green film at the bottom of my Keurig water tank going to kill me?

We've been using this Keurig for about a year, and we haven't always been the best at cleaning the water tank regularly. Recently I noticed a shiny green film around the rim of the black port at the bottom of the water vessel. I washed it immediately in scalding water and dish soap, and I thought I got everything. We continued using it, but this morning I found more of the film in a different spot. This time I poured boiling water into it, soaped it up, and poured it out. But I'm still not sure I got it all.

Is this just algae, or something more sinister? Is it from an alien source? If so, how soon before we stop worrying about our mortgage and student loans, and start planning the overthrow of your puny Earth governments and domination of your species?

Or, put another way, is this stuff going to kill us? How do we get rid of it? I really don't want to buy another Keurig. Does it help that the water is used to make hot beverages, or is that just wishful thinking?

posted by kythuen to home & garden (8 answers total)

Yes, it will kill you. You're dead now, in fact.

Sorry. It's algae. It's probably good for you. Clean it good with bleach and a srubby because any bit left will just propagate.
posted by cmoj at 11:38 AM on November 21, 2012 [7 favorites]

Green algae = invasive but edible. NBD. cmoj has it.

I'm going to guess your tank gets hit by direct sun for part of the day... Try shielding it or moving it where it won't be. Algae will still grow, but much slower, and your intermittent cleaning will keep it at the "unseen" level (which is where it is in most "clean" tanks across the world).
posted by IAmBroom at 11:47 AM on November 21, 2012 [1 favorite]

Our Brita pitchers are algae farms during sunny weather. We aren't dead yet.
posted by matildaben at 12:04 PM on November 21, 2012 [1 favorite]

It's almost certainly not toxic (as others have said) but it is admittedly kinda gross and could affect the flavor of your coffee. Were I you I would do as cmoj says and I would get in there with some bleach (soap won't really kill it, but bleach will) and clean it all out real good. I would remove the tank (if it is removable) and set it somewhere to dry completely. Then I would rinse it real well a bunch of times, until I could no longer smell even a trace of bleach (and I would probably rinse it once or twice more after that). At that point I would put it back in use and think no more of it.

IAmBroom's suggestion to keep light out of the tank is a good one too. Green algae is photosynthetic and needs light to grow. You could move it somewhere darker or cover it in a dark material of some kind.
posted by Scientist at 12:33 PM on November 21, 2012 [2 favorites]

Our Brita pitchers are algae farms during sunny weather.

We had this same problem until I installed a tap filter and we ditched the Brita. It didn't kill us but it was kind of gross to see this green slime at the bottom of the pitcher.
posted by Blazecock Pileon at 12:43 PM on November 21, 2012

White vinegar also works well to clean out this sorts of appliances and these sorts of algae/bacteria. Take a look at Keurig's info on maintenance and cleaning.
posted by CrazyLemonade at 12:45 PM on November 21, 2012 [1 favorite]

I think you are in no danger from this algae mini-bloom.

But I wouldn't be cavalier about it, either. Your instincts are basically right; algae aren't necessarily your little green buddies:

Health risk assessment of cyanobacterial (blue-green algal) toxins in drinking water.

Cyanobacterial toxins have caused human poisoning in the Americas, Europe and Australia. There is accumulating evidence that they are present in treated drinking water supplies when cyanobacterial blooms occur in source waters. With increased population pressure and depleted groundwater reserves, surface water is becoming more used as a raw water source, both from rivers and lakes/reservoirs. Additional nutrients in water which arise from sewage discharge, agricultural run-off or storm water result in overabundance of cyanobacteria, described as a 'water bloom'. The majority of cyanobacterial water-blooms are of toxic species, producing a diversity of toxins.The most important toxins presenting a risk to the human population are the neurotoxic alkaloids (anatoxins and paralytic shellfish poisons), the cyclic peptide hepatotoxins (microcystins) and the cytotoxic alkaloids (cylindrospermopsins). At the present time the only cyanobacteral toxin family that have been internationally assessed for health risk by the WHO are the microcystins, which cause acute liver injury and are active tumour promoters. Based on sub-chronic studies in rodents and pigs, a provisional Guideline Level for drinking water of 1 microg/L of microcystin-LR has been determined. This has been adopted in legislation in countries in Europe, South America and Australasia. This may be revised in the light of future teratogenicity, reproductive toxicity and carcinogenicity studies. The other cyanobacterial toxin which has been proposed for detailed health risk assessment is cylindrospermopsin, a cytotoxic compound which has marked genotoxicity, probable mutagenicity, and is a potential carcinogen. This toxin has caused human poisoning from drinking water, and occurs in water supplies in the USA, Europe, Asia, Australia and South America. An initial health risk assessment is presented with a proposed drinking water Guideline Level of 1 microg/L. There is a need for both increased monitoring data for toxins in drinking water and epidemiological studies on adverse health effects in exposed populations to clarify the extent of the health risk.

Symbiotic blue-green algae are the ultimate source of the cycad toxin which has caused epidemics of parkinsonism/ALS in the South Pacific, by the way, and while Googling for a citation for that assertion, I ran into a startling and rather sensationalistic story in Pacific Standard, a muckraking, left-leaning environmental magazine, about possible health effects of of algal toxins in US water supplies: Was Lou Gehrig’s ALS Caused by Tap Water?
posted by jamjam at 5:05 PM on November 21, 2012 [2 favorites]

jamjam, that's a lovely scare-article about ZOMG! ICKY THINGS R GOING 2 KILL U!!!, but the reason "blue-green algae" are called "blue-green algae" is, surprisingly enough, because they are blue-green in color.

The OP did not describe blue-green colored algae. their algal bloom is green. Green algae is not poisonous. In fact, various species are being examined as food sources, since they are the most efficient plants at trapping sunlight over a given, large area.

I'll stand by my non-scare-story statement: it won't hurt you. But I too will clean it off, because it looks gross; however, I've been known to drink the green-hued bottle of water in my car before cleaning it, because I was thirsty.
posted by IAmBroom at 7:24 PM on November 24, 2012 [1 favorite]