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- Hacker News
- 61 factories in 39 countries is impressive. But I'm always curious about the real world failure rate. How many of these filters get installed and then crack, or clog, or just get used as flower pots?
- When I was a kid, we'd go camping, and we had these water filters that you would pump water through, and they would filter it.
It was ceramic, and I think it was the same idea, but we used a pump to force the water through (like a bicycle pump).
- That guidance comic is a disaster. The dirty water is the same color as the clean water.
Very confusing.
by brador - There is something very satisfying about sawdust being a feature rather than an impurityby SwtCyber
- I wonder if you could achieve the same effect more easily/consistently using cement. It's basically how aquifers "filter" water. Limestone is naturally permeable unlike fired clay.. were you need to control the porosity. I'd imagine cement mixtures are much easier to handle and you can make arbitrary shapes (higher surface area and higher hydraulic pressure to increase the flow rate)by geokon
- Maybe, although I think cement would trade one set of manufacturing problems for anotherby SwtCyber
- Cement is not easy to make permeable. With the clay the trick is to put combustible material in the mix which gets burned off and leaves micropores behind.by rdtsc
- Nice. It's like a mini version of a slow sand filter.[1]by Animats
- by rainworld
- I'm in Antigua, Guatemala where the embedded video is from. As the video says, it may be "low tech", but it's not like something you can do very easily for yourself. Ecofiltro is everywhere here. But, it is more expensive then I would have thought - maybe $30 for a clay pot and $50 for it's container.by ks2048
- For far less money than that you can buy a regular particle filter...
- There is a company[1] in Indonesia that actually makes very nice versions of this tech.by fastball
- I may have had an early version of this at home in Indonesia as a kid. Given how close we were to both sea level and the equator, the fact that the water was cool, even when site power failed for days, was bliss!by com
- From https://www.terrawaterindonesia.com/the-filter:
> A single Terra filter purifies up to 42 liters of safe, pure drinking water a day, equivalent of 2 and a half plastic gallons.
Someone should tell them to check their math.
by treetalker - That ad claims it removes microplastics. I was led to believe there are few easy ways to accomplish such a thing. Is this a, "Well technically, we started at 100ug/mL and ended at 99.8ug/mL => reduction!" or is this a meaningful improvement in water quality? The pot looks to just be clay + charcoal + silver - which is not significantly different from other home water filtration systems.by 3eb7988a1663
- Hmm just shared this with someone who works in this space in India, they got angry.
> It doesn’t work for 3rd world contaminants.
> White people have been making these for years. Doesn’t work
> We need hard TDS removal also
And the ceramic ones apparently are also bad:
> we had one of these for many years while growing up. the ceramic candles got fungus on them
Viruses are the bigger threat I think and just a filter like this will not stop them HepC and the like would be easily transmittable. Not really “safe”, maybe at best “better than nothing”
by seer - seems like he or she might have an anger and racism problem? "white people have been making these for years?"
PERHAPS instead of being angry at white people, they should look a bit into what they do in their own backyard.
yeah, downvote away :) but it doesnt make it not true, and thats why the downvotes will sting the downvoters so hard
by redeeman - I do not know whether this is what they meant, but in many places the biggest threat is now industrial pollutants not infectious diseases.by graemep
- Would would want to chlorinate the resulting water, these filters are only going to remove large particulates.
Clay/sand water filters have been in use for a long time, some from the roman period are still in use.
by 8by3 - Ceramic filters are very common in Brazil, used in clay recipients which also keep the water cool even in summer without spending energy.
https://g1.globo.com/saude/noticia/2026/03/14/filtro-de-barr...
by cassianoleal - The passive cooling is almost as clever as the filtrationby SwtCyber
- This and the low-tech electrical shower-head are the two everyday Brazilian things that never cease to amaze me.by weinzierl
- Mostly in rural regions, but the 'filtro de barro' water from your grandma's house beats ANY expensive filter you can get, haha!by hei-lima
- Using clay to cool water in the summer is actually the original purpose of olla pots in the Southwest. They cool the water through evaporative cooling
Andy Ward demonstrated this https://www.youtube.com/watch?v=TBos0j0FszU
by culi - This sound like Ghara https://en.wikipedia.org/wiki/Ghara which is very common in rural areas in subcontinent. It keeps water cool in summer. It gives water a very nice earthy taste. Ghara is usually paired with a clay bowl to drink water.
If you can buy a clay bowl or glass, get it and keep water in it on your side and drink from. It will be cool and will have a very nice earthy flavour. But not all clay pots are same quality. Some are not very porous and won't cool the water or give you different taste.
by smusamashah - Sri Lankan here. We've had this type of ceramic filter here for at least 35 years: https://cdn.shopify.com/s/files/1/0182/4859/7582/files/Ultra...by hliyan