My tap water has been giving me trouble. It tastes musty and a bit moldy, with a lingering cloud of unpleasant aftertaste. I don't filter my water — I've never seen the need. City water has always tasted fine to me. So why this taste now? Is it my faucet? My pipes? Is it all in my head? None of the above. There's a reason my water tastes musty, and yours may too. Do you know why?
The most likely reason for the taste in my water is algal bloom.
In the summer, when there is light from the sun and plenty of warmth, algae can bloom on the surface of lakes, reservoirs, and other water sources. While the bacteria is scrubbed from the water during the water treatment process, the moldy taste the algae imparts to the water can be detected at extremely microscopic levels. Some people are especially sensitive to mildew and musty tastes in food (I noticed this well before my husband did, for instance) and it can affect them more.
Here's what my city water website has to say about this problem:
Occasionally Columbus water has an earthy, musty or fishy taste and odor. These seasonal phenomena can be caused by the bi-annual turnover of our city reservoirs, or with the presence of varied algal blooms in the reservoirs or rivers. It is important to note this taste and odor poses no health concern but one of aesthetic quality. - Source
This taste should fade away as the weather gets colder and the algae dies off. But it's distinctly annoying now, and for the first time I'm considering buying a water filter. Until then, I'm drinking my water with lots of lime slices.
What does your water taste like right now? Do you notice seasonal changes in your tap water? Do you filter your water at all?
Related: Friendly Reminder: Refill Your Filtered Water Pitcher Before You Pour a Glass
(Image: Yellowj/Shutterstock)
Bacsac Bacsquare 04...

My water does taste like mold, but I thought I needed to clean my re-usable bottles better! I'm so glad I didn't fill them with bleach! Thanks so much for this!
Nope. But we filter all drinking and cooking water.
My water tastes a little off. I thought it was almost metallic, but it probably is more of a moldy taste. We have a filter in the sink, but that only does so much.
i live in akron, ohio and this happened a couple of years ago, worst tasting water ever!! i'm not sure that a filter would remove the taste. i just resorted to buying big jugs of distilled or ro water.
The problem is that taste is subjective: to placebo, to other chemicals. We're very fortunate (ours was voted the best tasting tap water in 2008) but I think it's because our state is very proactive in protecting our water supplies. Pollution and and warming will only make these problems worse, so citizen action is important.
This really depends on the source of your city water supply. If the water supply originally comes from groundwater wells, seasonal changes in water quality are less likely to be an issue, but if it comes from a river or lake, there can be seasonal differences in the taste of the water. Here in North Bay, Ontario, Canada, our water comes from a very deep, cold, clear spring-fed lake, so our water is wonderful all year round. Your municipal water facility puts a lot of time and effort (and your tax dollars!) into making tap water SAFE to drink, although there may be a slightly funky smell or taste at times. A Britta filter is all you need to take away any off-taste.
PLEASE don't resort to buying bottled water: it's such a wasteful, garbage-producing way to get drinking water, and the actual water quality isn't nearly as carefully regulated as tap water is. Here in North America we are very fortunate to have unlimited safe drinking water coming out of our taps; we should realize what an amazing luxury this would be for so many people in other parts of the world.
Do filters really pick up odd tastes/odors in water? I had no idea.
We found it can also be something far simpler, the aerator in your faucet, it's a good to regularly slip that out and clean or replace it.
They pull our water from the bottom of a lake (which is really just a dammed up section of river). I usually notice the algae smell in the late fall/winter when there's more lake turnover.
Ours tastes funky after being filtered. I'm wondering if either the fridge where we store the filter jug is making it smell bad, or if our pipes are lead or something and that is why the water tastes weirdly sweet and gross. In any case, we are having a plumber come out and take a look!
the filter will not remove that awful taste. if you haven't experienced the algal bloom water, you have no idea how awful it is. and ps: buying a refillable 5 gallon jug for water is not wasteful or irresponsible.
@Joi it is wasteful in the sense that the towns have a responsibility to provide you with clean, decent tasting water. Plastics are designed to last forever. So why are they being made into disposable products? It should be against the law. Water should be sold in glass bottles, and realize that buying fossil-fuel based plastic ADDS to pollution that causes the algal blooms in the first place.
@Emmi: Good for you if taste is part of the requirements where you live, here it's just a matter of the water being chemically good to drink. Taste is not a requirement.
I filter my tap water with Brita, so I dont notice that taste... But I do notice over-softened water... My thirst is unquenched even after drinking gallons of that... :(
Oh, I live in Cbus and I noticed a change in the flavor, as well! I had not filtered my water before this, but I did purchase a Brita-like system to combat the odd taste.
I'm so glad you posted this, because I've had issues with my water smelling off, and I never knew why. It may not be the same issue, but it sounds like it could be. For me, a filter does not get rid of the problem, but since my issue is primarily with the smell, rather than taste, using a water bottle or a (reusable) cup/lid/straw where I don't have to smell the water as I'm drinking really helps.
Also, I find ice cubes to be especially smelly, so I would advice avoiding them.
@ChristineM when did I say taste was a requirement? Ours tastes good because the town is vigilant about water cleanliness and reducing chemicals. If your water tastes bad, your town probably isn't doing enough to reduce chemicals or pollutants.
I live in Chicago & am on the city water grid aka I get lake water. Buying a water filter won't do anything to get rid of the taste. It's already filtered by the time it comes into your house.
I grew up being spoiled by the wonderful water in NYC. Then I came down here, and discovered that not all city water is the same. The water here tastes (and I mean TASTES) of chemicals, primarily chlorine I think. I couldn't live without my Brita filter. We get an annual report from the Water Department assuring us that it's safe, which I believe it is. But I won't give up my filter, which does get rid of the taste.
While areas do go to great lengths to make water 'safe' to drink, that's not always necessarily the case. Most tap water has traces of pharmaceuticals, antibiotics, and hormones (from birth control pills) in it, not to mention the flouride, chlorine, and other weird chemicals. And while you'd think that North American tap water is all safe to drink, there are some areas where peoples' tap water comes out brown, or can be set on fire (fracking areas) and is most definitely not safe at all. *shrug* We have a really fancy water filter that's supposed to remove all that stuff in the kitchen, and another one in the shower (too much chlorine here in LA; gives me eczema) but if I couldn't afford those I'd totally buy big jugs of water too. We're all responsible for what's going on on the planet, and personally I think we should all try as hard as we can to make as little waste as possible and not use up resources irresponsibly, but having safe, clean drinking water is so damn important, and I wouldn't drink my tap water here, regardless of how the city says its safe...
I'd like to know why people think bottled water is safer and cleaner than tap water even after using a filter. It's well known that many bottled water companies ARE using tap water. Also what do we think they're using to filter it, fairy dust?
And let's not forget that algal blooms are generally caused by an overabundance of nutrients in the water...nutrients (phosphates and nitrates) from fertilizers, urban runoff, fecal matter, and other sources of pollution. Yum! While we're talking to our towns about tastier/safer water, let's also work on having them build riparian buffers and educate folks about how to use lawn and agricultural chemicals in a way that results in the least possible pollution.
Ours is AWFUL year round here.... and REAL bad when the algae goes nuts.
Our cities' site says the same thing- that it's harmless..
it is nasty tasting though.
I'm lucky enough to live in the city awarded "Best Tasting Tap Water" by the American Water Works Association- my water tastes like nothin' but wishes and dreams and leprechaun kisses!
Thanks for the post!
I filter my water at home but have experienced that mouldy taste while traveling. Sometimes it's so subtle that i think i'm going crazy, it's good to know that's not the case!
I find that the taste is a big issue but i think i'm much more concerned about bacteria and viruses.
I read this post, which covered some good elements of filtering water: Why filter water.
What filters does everyone use to remove the mouldy taste?
What city are you in now with the chemically tasting water?
Ours just started tasting funny a few days ago. So the filter does make it taste normal again? I hate the bottled stuff.