How safe is this water filter?

I’ve looked at other water safety threads, but I still want to make sure about my particular situation. The landlords at my last two apartments told me the filter under the sink will allow me to drink the water directly for three years, and then I need to have the filters changed. At my current apartment, the shuidian just told me that the filter I’m using must be changed every six months, and that it’s not safe to drink in any case. He said you must take the extra step of boiling or using another filter, like a Brita. And I’ve been directly drinking a lot of water from this filter every day for three years, so I have these questions:

  1. have I damaged my health in some irreversible way, or have I just been at higher risk and any ill effects have been temporary?

  2. He said the problem is microbes, so I’m wondering if after three years a person (in their ignorance) becomes accustomed to the microbes so that it’s no longer an issue to drink from this filter?

I’ve attached an image of the two-stage filter. I’ve had people tell me this is good enough, but if it’s not, then why even bother changing it every six months?

Since there’s no way to tell what kind of filter those are, these are some of the things I know:

  1. I haven met many landlords that would put up water filters in apartments. Having it there is a plus.
  2. There are many different types of filters. Typically they need to be changed every 6 months or even less.
  3. Some high end filters, such as 3M’s AP903 says to replace filters every year.
  4. Usually the company that installed the filter will try to schedule a filter change when it is time to change it. After all, that’s how they make money.

The shuidian went out and got me one of these filters:

He said you fill that tabletop filter using the water drawn through the undersink filter. He said the tabletop filter lasts many years, but you still have to change the undersink filters every six months. What are the options in a one-shot deal? Meaning, is there any sort of tabletop unit that doesn’t require pre-filtering from the undersink filter, which has to be changed frequently and with difficulty?

Any estimates on the health effects? Are there long term hidden health effects, or if you don’t get sick right away, then the water was probably OK even with the lesser quality filtering?


He said you fill that tabletop filter using the water drawn through the undersink filter. He said the tabletop filter lasts many years, but you still have to change the undersink filters every six months. What are the options in a one-shot deal? Meaning, is there any sort of tabletop unit that doesn’t require pre-filtering from the undersink filter, which has to be changed frequently and with difficulty?

Any estimates on the health effects? Are there long term hidden health effects, or if you don’t get sick right away, then the water was probably OK even with the lesser quality filtering?[/quote]


I think if you want a good filtering system, undersink version is the minimum. A good system typically uses 2~3 types of filters.

Types of common filters:

  1. Reverse Osmosis (RO): Best kind of filtering you could get. Half of the water you put in will be filtered out. Outcome is almost pure water, which is not the best drinking water. Chlorine used in tap water tends to damage the membrane that filters the water, so probably needs frequent replacement. Needs a pump to pump the water through the membrane. Pump equals to noise.

  2. Water-Ionizer: Not a lot of actual filtering. It uses weak electrolysis to separate water into alkaline ionized water, the part you end up drinking, and acidic ionized water. Super alkaline ionized water can be a disinfectant, and the process can extract calcium sulfate by dumping the acidic ionized water. But other than that, unless you believe drining alkaline ionized water improves health, it doesn’t do much for the quality of water.

  3. Activated carbon filtering: Activated carbon can filter out impurities, germs, heavy metal particles, organized pollutants and chlorine.

  4. Ultraviolet lamp: Kills germs and other things that filtering can’t get rid off.

  5. Minerals: In Taiwan they often use Maifan Stone. In case the water is filtered to an extreme, where no mineral is left in the water, people would add this stage to restore mineral content.

Some of the good systems I see out there uses some combinations of the above. The one that makes sense to me would be Activated carbon filter + Minerals + Ultraviolet lamp.

Imagine getting water through that many filters. A pump is usually needed. So, a sink-based filtering system is the minimum. I currently live in a crappy apartment, and I use a counter filter bottle to make myself feel better…

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Have you noticed any swelling of your swim bladder? If not, you may have lucked out.

@hansioux, it turns out that new tabletop thing isn’t a filter, but a water boiler. Where does boiling fit in your chain of filtering? I thought some people consider this the be-all-end-all of purifying microbes, but the shuidian said not to put tap water directly into the boiler, that it should be filtered first. Granted, overkill won’t make the water more dangerous, but I really don’t like the idea of using the only two choices this device offers: very hot and extremely hot, particularly during the warm weather. It’s also a real pain in the ass given the small space I have, and it’s making my “kitchen” space unusable. If adding a third stage portable Brita filter offers the same degree of security, then this was a waste of $2500.

I went to Mackay hospital to see if there was anyone who had any idea of the optimal way to deal with the water issue, but they said no. Everyone has an idea of what’s best, but they told me they couldn’t think of even a doctor there who would have an informed opinion as to acceptable risk because native Taiwanese are happy to drink nothing but boiled water (tea) or bottled. They gave me the address of Taiwan Water Corporation near Gongguan, so I’ll give that a try. People seem pretty comfortable with public drinking fountains, so if I could get it down to that level of risk without a big piece of equipment in my apartment, that would be nice.

You defiantly don’t want to go by public opinion. People are generally horribly informed on what is safe. Personally, I drink imported water. It’s not really that expensive.

Yeah. I just talked to another Taiwan friend who told me that no one’s really sure what the problem is, but they’re afraid to take any chances, so they double filter and then boil or Brita. I thought people here prefer drinking hot water, but he told me a lot people don’t and that they do it because they’re playing it safe. I wouldn’t disagree with that. I agree buying water looks like the safest bet, but that’s just too impractical (and expensive) for me if the other conservative options are viable. Are there any delivery services here that bring you those giant jugs and rent you one of their floorstanding units? I’ve never seen those water jug home delivery trucks here, but they’re common in the U.S.

My friend said there are two aspects: microbes and chlorine from the treatment plant. I suppose that means the undersink filter is for chlorine and the boiling is for the microbes. But you would think that the chlorine was for the microbes. He agreed, but said people take the extra step anyway. He thought the extra step isn’t necessary, particularly if the unboiled water hasn’t given you diarrhea, but my concern is that constantly ingesting bad microbes could cause problems you don’t see, possibly much later. Unless the Water Corporation tells me that the additional step of boiling or Brita-ing provides a measurable benefit, I also don’t want to take a measurable risk.

So a little research shows that Brita claims to do nothing more than make water taste better. So that would mean people who undersink filter then Brita are doing nothing more than undersink filter. So it comes down to boiling or not, but doesn’t boiling kill the same things the chlorine is used for? It’s certainly not a case of some very dangerous microbe that needs to be eliminated, or else it wouldn’t be safe to expose all your skin to the unfiltered water in the shower.

We use one of these, on the insistence of my father-in-law: … 53929.html

It’s expensive, loud, and inconvenient, but I’m pretty sure it’s the safest thing there is.

EDIT: Or I was pretty sure, until I wrote this post and thought “maybe I should Google that”. Now I’m much less sure!

Raised in Taiwan, i too am uncomfortable drinking water from the tap. Even though i have lived so long now in the USA, i still don’t like doing that with any regularity. HOwever, if you go to a restaurant, starbucks or whatever in the USA, the drinking water they provide is straight from the tap. Some establishments have a filter of some sort to make the water taste better.

What I do in Taiwan? USe Brita to filter the water , then boil it.

What I do in California? Use Brita to filter the water, then boil it.

Filters usually only filter out heavy metals (which boiling does NOT get rid of) and large particles. Boiling is needed to kill any germs that may be present.

And water can carry many diseases !!

7/11 (and the like) in Taiwan use a fairly sophisticated water filter for their soda machine. It does not boil, but triple filters normal city water for those machines.

Seems to be healthy enough.

[quote=“tommy525”]Filters usually only filter out heavy metals (which boiling does NOT get rid of) and large particles. Boiling is needed to kill any germs that may be present.

And water can carry many diseases !![/quote]
Is the water delivered to the tap in Taiwan treated with chlorine?

I’ve been here a few years now and have never bothered with filtering water. I’ve brushed my teeth twice a day and made copious amounts of tea using boiled tap water and i’ve never had so much as a dose of the trots.

I wouldn’t advocate anyone else being as reckless as me. This is just my experience.

Taipei water bureau claims its water when it leaves its treatment plants (with chlorine added) is safe to drink. But individual water pipes in individual homes may vary.

Best is to boil before drinking. Rinsing the mouth after brushing teeth seems ok. Iv done that for eons in Taiwan.

Well water is not safe though. Often contains Arsenic and other heavy metals. Water in Ktown seems to contain arsenic as well.

So most people in Ktown buy processed water for drinking, FAIK.

Then the danger from local building pipes is microbes, not heavy metals or other inorganic contaminants? In that case, what’s the function of the undersink filters? I mean, boiling can only be to kill microbes, yet the three apartments I’ve lived in have come with filters as if filtering is the necessary line of defense and boiling is optional. Those apartments were all pretty new, so maybe that’s why they didn’t recommend boiling. So is the filter merely for taste?

A proper filter CAN filter the water enough to keep microbes and metals from entering your system. But I would only trust those massive filters you see in 7/11 . And of course, even those have to be regularly serviced.

Personally, i would still drink only bottled or boiled water. I would filter it prior for taste.

You could also (if you like to have water in the fridge for drinking) get one of those brita pitchers. Boil and let cool water and then pour into the Brita Pitchers and put that in the fridge. YOu will have ready access to cool and CLEAN water.


The first thing I have to say is a Brita is a waste of money, as all it will do is make the water taste better, and may remove anything floating in your water. The distillation system above by Brendon is good, it will remove microbes, but it will leave behind many contaminants, as everything with a lower boiling point than water remains. The best process is reverse osmosis, and it is an all in one unit that will remove everything from the water, including microbes. And while it is susceptible to chlorine as mentioned above, this is why most systems come with a carbon filter or two to remove chlorine before reaching the membrane to ensure it will last it’s life. They also do not need a pump, unless your water pressure is low, as my water is above 50 PSI, which is minimum, so I did not need one. I got my system from here, … -di-system. Filters are generally changed every 6 months, except for the membrane, which I change every 2 years.

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Do they sell something like that locally, maybe at Carrefour? If they’re labeled in Mandarin, how do you say “reverse osmosis”?

Does a reverse osmosis system do anything substantially different than my current 2-stage system, which is now followed by the boiler? Because the space under my sink might be too small to fit the kind of system you linked to. The boiler’s inconvenient, but not horribly so.

We use an RO system, similar to the one under your sink. Something like this

It has the same sort of pre-filtration, i think 4 in total, then finally reverse osmosis, it does not have UV. For the osmosis to work it uses a pump. So there is some pump noise as the tank refills, however as it is under the sink you have to be real close to hear it.

We use that water for drinks (hot and cold) and cooking. That said, no idea if it makes the water ‘safe’ to drink but we do…

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I went to the Taipei Water Department and got all the info, which will be the same as some things already posted in this thread. Other cities may differ, but it’s as safe to drink Taipei water straight from the tap as other advanced countries, and it’s significantly safer than the water I’ve been drinking my whole life, which has never been anything close to unsafe.

links to Water Department info: … &mp=114012 … &mp=114012

There are two health issues: microbes and chlorine. The level of microbes is fine. I’ve always thought the fear of ingesting an unacceptable level of microbes was irrational because showering will introduce the same feared microbes via your orifices, mucous membranes, and skin. (I personally have been poisoned via the skin.) It would be really dumb to shower in water that’s unsafe to drink due to microbes. As for chlorine, the residual amount is far below what I’ve drunk my whole life, and lower than most other countries that have data. You can, however, remove more of the chlorine by boiling for five or more minutes or filtering with charcoal, so at least there’s a rational basis there, even though the residual chlorine is well within the limits of acceptable risk. There’s no danger of microbes contaminating water that has stood for three days or less. So if water is flowing regularly, then old buildings are just as safe as new ones. After three days, the chlorine level becomes low enough to allow microbes to multiply.

To sum up, the kind of two-stage undersink filter in my picture has no health related benefit. It does make the water taste better, but the WD said better taste invariably means what that person has become accustomed to. People get used to a filter they believe in, then any other taste becomes subjectively bad. That jibes with my experience, and what’s more, when you install a new filter (or new equipment), you get that new filter taste, which isn’t all that great either. It’s just that you believe the new filter taste signifies healthiness, so you accept it and become accustomed. They said natives’ irrationality regarding water safety is higher here than in other countries, despite Taipei’s water meeting the highest international standards. That seems harmless enough, and maybe there’s some marginal benefit to eliminating more chlorine or constantly taking action against microbes so that if there’s a sudden disaster, you’ll be protected. You can also lessen your chances of being struck by lightning by never leaving the house when it’s raining. Or perhaps if a giant government conspiracy to misrepresent the water quality ever develops, you’re clear there.

Food-based paranoias spread fast and go quite deep, too. For example, the famous cases of Church’s Fried Chicken and Bubble Yum. With commercial food products, though, there’s a lot of money behind quashing false rumors (and true ones, too) because owners’ wealth is at stake. But this water thing looks intractable, and the marginal or even zero reduction in risk isn’t exactly harmless when you consider the environmental impact and wealth redistribution caused by the bottled water industry. I think the advanced filtration devices and boiled water machines don’t represent the kind of cash cow that bottled water does, and boiled water has a practical use if you like to drink hot beverages. But I’d rather reclaim my counter space than be totally prepared for tea 24/7. Anyone want a slightly used this?: