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!
> 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.
ssl-3•Aug 16, 2026
Those are plastic gallons. Plastic gallons are similar to treetalker gallons and ssl-3 gallons, in that all of these units share the property of being different compared to US gallons.
(The ssl-3 gallon is particularly strange: It isn't even a measure of volume at all.)
SoftTalker•Aug 16, 2026
Heh never heard of a plastic gallon. I was imagining a plastic gallon jug such as a milk jug.
fastball•Aug 16, 2026
Yeah, in Indonesia (and other parts of the world), the 5-gallon jug you would stick in e.g. a water cooler is called a "water gallon".
SoftTalker•Aug 16, 2026
I assume it's a local/informal unit of measure? DDG doesn't know what a "plastic gallon" unit is.
fastball•Aug 16, 2026
It's not really a unit of measurement but rather just what you'd call the container[1], which in turn is 5 gallon / 19L. But nobody says "My 19L water jug", they they just say "My water gallon".
Since most people in Indonesia get their drinking water from these jugs, stating this filter's output in "gallon" terms is just the easiest way to communicate potential savings etc (since people pay per jug, so they think in jug terms, not in any other unit of measure).
TIL! Not the first time I've made a mistake on account of failing to detect that a different English was being used.
3eb7988a1663•Aug 16, 2026
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.
gizmo686•Aug 16, 2026
Filtering out microplastics is not particularly difficult. I just checked the first water filter brand that came to mind, and their independent test results [0] reported no detectable microplastics after filtration [1].
Having said that, the linked website above does not inspire much confidence. They have independent lab testing, which is good. However, that testing appears to only cover bacteria; and even their, only two types. Their lab testing also does not indicate any sort of methodology, and it is not clear if the lab was even attempting to test the filter, or if they were just testing the filtered water.
[0] Funded by them, and reported on their website
[1] Their sample had a known quantity of microplastics, of which they had a 75% detection rate for their control sample.
Aboutplants•Aug 16, 2026
“The pot looks to just be clay + charcoal + silver - which is not significantly different from other home water filtration systems.”
Ah, the at home water filtration systems that encapsulated in plastics! Though the benefit of clean water likely makes any potential plastic contamination from the filters moot
PetitPrince•Aug 17, 2026
Are microplastic produced predominantly by plastic leaching out of objects, or is it coming from garbage that got mechanically pulverized, UVized, and contaminating water sources ?
fastball•Aug 17, 2026
Well the difference is that most home water filtration systems (e.g. Brita et al) are made out of plastic, so even if their filters do reduce microplastic levels, making that claim to consumers ("our plastic filters help reduce plastic in your water") might be a hard sell.
tlavoie•Aug 17, 2026
Does the water end up including some of the colloidal silver? As it happens, there is someone living in my area who has taken colloidal silver in some fashion for ages, with the side effect of turning the skin a ghastly grey hue. I can't say how they're doing for infections and related illness, other than that they probably also have fewer in-person interactions with other people.
cassianoleal•Aug 16, 2026
Ceramic filters are very common in Brazil, used in clay recipients which also keep the water cool even in summer without spending energy.
This and the low-tech electrical shower-head are the two everyday Brazilian things that never cease to amaze me.
mlinhares•Aug 16, 2026
Being poor sucks but at the same time being poor also makes you find alternative solutions to the incredibly expensive solutions first world countries use today. I really wish Brazil can invest heavily into renewables and free itself from oil and electrify even more of everything we do.
m463•Aug 17, 2026
> electrical shower-head
Is that for electrically heated water?
I know that in the US on-demand electric water heater uses an enormous amount of electricity, like 100 amps.
kawera•Aug 17, 2026
Brazilian electrical shower-heads use 20 to 30 amps max.
dtgriscom•Aug 17, 2026
At what voltage? (I understand Brazil has districts with both 127V and 220V mains.)
In the Sri Lankan context filters are more important than ever, but I think activated carbon ones? Water is (heavily, I think!) chlorinated but pollution is pretty bad.
culi•Aug 17, 2026
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
Yes you are losing water but the phase change energy of water is immense, very little needs to be evaporated comparatively for immense cooling.
WJW•Aug 17, 2026
Yes it does. But it might be worth it if you have more water than cooling capacity, or if you have an otherwise very dry house that you'd want a little but more humidified.
SwtCyber•Aug 17, 2026
The passive cooling is almost as clever as the filtration
smusamashah•Aug 17, 2026
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.
lukan•Aug 17, 2026
But there is no filter in the Ghara?
ChrisMarshallNY•Aug 16, 2026
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).
geokon•Aug 17, 2026
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)
SwtCyber•Aug 17, 2026
Maybe, although I think cement would trade one set of manufacturing problems for another
rdtsc•Aug 17, 2026
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.
ks2048•Aug 17, 2026
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.
londons_explore•Aug 17, 2026
For far less money than that you can buy a regular particle filter...
SwtCyber•Aug 17, 2026
There is something very satisfying about sawdust being a feature rather than an impurity
Animats•Aug 17, 2026
Nice. It's like a mini version of a slow sand filter.[1]
It took me a while to realize that this is not from "lowtechmagazine".
brador•Aug 17, 2026
That guidance comic is a disaster. The dirty water is the same color as the clean water.
Very confusing.
seer•Aug 17, 2026
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”
graemep•Aug 17, 2026
I do not know whether this is what they meant, but in many places the biggest threat is now industrial pollutants not infectious diseases.
8by3•Aug 17, 2026
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.
redeeman•Aug 17, 2026
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
12 Comments
[1] https://www.terrawaterindonesia.com/
> 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.
(The ssl-3 gallon is particularly strange: It isn't even a measure of volume at all.)
Since most people in Indonesia get their drinking water from these jugs, stating this filter's output in "gallon" terms is just the easiest way to communicate potential savings etc (since people pay per jug, so they think in jug terms, not in any other unit of measure).
[1] https://m.media-amazon.com/images/I/61fpdmJYUuL.jpg
[0] Funded by them, and reported on their website
[1] Their sample had a known quantity of microplastics, of which they had a 75% detection rate for their control sample.
Ah, the at home water filtration systems that encapsulated in plastics! Though the benefit of clean water likely makes any potential plastic contamination from the filters moot
https://g1.globo.com/saude/noticia/2026/03/14/filtro-de-barr...
Is that for electrically heated water?
I know that in the US on-demand electric water heater uses an enormous amount of electricity, like 100 amps.
https://www.worldstandards.eu/electricity/plug-voltage-by-co...
https://en.wikipedia.org/wiki/Ceramic_water_filter
In the Sri Lankan context filters are more important than ever, but I think activated carbon ones? Water is (heavily, I think!) chlorinated but pollution is pretty bad.
Andy Ward demonstrated this https://www.youtube.com/watch?v=TBos0j0FszU
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.
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).
[1] https://en.wikipedia.org/wiki/Slow_sand_filter
Very confusing.
> 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”
Clay/sand water filters have been in use for a long time, some from the roman period are still in use.
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