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New, slippery toilet coating provides cleaner flushing, saves water (phys.org)
195 points by howard941 24 days ago | hide | past | web | favorite | 147 comments

Hi Everyone! Birgitt here from spotLESS Materials -- we are commercializing this technology and some of the authors of the Nature Sustainability paper are part of our team. I'll try answering some of the questions I'm seeing. Would love to hear your feedback!

Check out our products at: https://www.spotlessmaterials.com/shop

Check out the full research article here: https://www.nature.com/articles/s41893-019-0421-0#citeas

Edit: Let me answer a few of the common questions here:

1. Is it easy to apply? We designed our coatings to be applied in minutes with just a spray bottle and a paper towel/cloth.

2. Regarding durability: Our coating consists of two parts - the first part is the formation of a nanohair layer, which is permanently bonded to a substrate (e.g., toilet surface or glass). This layer itself is very liquid-repellent and sludge-repellent and does not require replenishment as it is permanently attached onto the underlying substrate.

The second part is the lubricant, which is infused into the nanohair layer (like a nanoscale sponge absorbing the lubricant). The combination of the lubricant and the nanohair make LESS coating super slippery against liquid and sludge-like substances. The lubricant layer will wear off over time depending on the frequency of use. For typical use in a toilet environment, the lubricant will need to be replenished after ~500 toilet flushes and can be reapplied by a simple spray process.

3. Regarding the environmental friendliness of our coatings: Our product is based on silicone. It has been shown in the scientific literature that silicone can be decomposed naturally in soil within 4-7 days. It breaks down in silica, water, and carbon dioxide.

Ref.: Graiver, D., Farminer, K. & Narayan, R. A review of the fate and effects of silicones in the environment. J. Polym. Environ. 11, 129–136 (2003).

> 3. Regarding the environmental friendliness of our coatings: Our product is based on silicone. It has been shown in the scientific literature that silicone can be decomposed naturally in soil within 4-7 days. It breaks down in silica, water, and carbon dioxide.

"Based on silicone" does not mean "degrades like silicone." It also doesn't mean your coating will behave like the silicone "in the scientific literature." If I toss a silicone spoon in the ocean, it won't be gone in a week. You can make plastic out of wood. That doesn't make it biodegradable. There are different kinds of silicone. Some degrade quickly, some don't. Some is toxic as it degrades. It can accumulate in fish like plastic, etc.

Without knowing how the coating wears off (in chunks when toilet is cleaned, etc), it's hard to compare. Also, if it's not actually silicone, we shouldn't be pretending it acts like it is.

Have any independent environmental assessment been done? What happens when you drink it? What happens when you feed it to fish?

I have concerns because the product descriptions and images don't say the amount anywhere or how long it should be expected to last and under what conditions - kinda feels scammy.

For example, is it 1oz or 20oz? Honestly, it looks like a tiny sprayer - maybe 1oz? How far will it go? Will that 1oz. treat 1 sink/toilet or 10? How long will it last?

I did see that the article says "...researchers also predict the coating could last for about 500 flushes". OK it "could" last 500, or it could last 1. The real question is how long "did" it last when you tested it and what should a normal person expect? Does urine affect it's longevity differently from poop? What happens if you use a toilet brush on it, or use various cleaning chemicals - will that shorten it's usable life?

e.g. from https://www.spotlessmaterials.com/store/p10/Sink_%26_Fixture...:

"Sink & Fixture Coating SKU: S008191114 $15.00 Our Sink & Fixture Coatings are popular amongst our early users. These coatings can be applied to any ceramic surface and are specially formulated for high-touch ceramic surfaces like sinks, toilet exteriors, etc. After application, you’ll feel the difference. Our coatings are ultra smooth to the touch. It’s that same smoothness that makes the surfaces easier to clean. With these coatings, cleaning ceramic surfaces required less time, effort, and cleaning chemicals. Do not apply coating to floors -- it is slippery. This coating can be refreshed with our Maintenance Spray."

I also have the same concerns about your product.

Likewise. At massive scale, conserving water by adding more artificial/industrial runoff doesn't seem like a good approach, at all. This version of the world is behind us.

Given that the goal of this product is to reduce the water usage, it would mean that you not only add something to the water, but also reduce the total amount of waste water, thus increasing the concentration.

Can any remains be sorted out at common water treatment facilities?

Generally small particles like micro-plastics are too small to be filtered by treatment facilities. My assumption here would be no. It could be that a chemical/heating process in a treatment facility could accelerate the breakdown. That's just pure speculation though since we don't know enough to judge.

Time to get gross here.

I have been dealing with neck/mouth cancer for a while and using a feeding tube for about half of my calories. My movements, depending on the alignment of the stars resemble the mortar used to join cinder blocks together. It is explosive and sticks to the bowl. I can flush ten times and it doesn't budge and I have to manually get in there.

So I am going to try this. It is cheap enough and even if it helps a little will be a huge quality of life improvement.

Three months into chemo it wasn't great dealing with every trip to the bathroom being a chore. And combine that with the fact that my immune system was basically non-existent. Lingering fecal matter was a health risk.

You might want to consider marketing to radiologists, oncologists, and nutritionists. Tons of fellow tubers out there.

I wish you lots of strength and an abundance of good luck.

Try a parachute. Put some to down in the water before you let loose.

Sadly, we are dealing with a Jackson Pollock situation.

You sir, are an ace. I wish you all the best.

I just thought of another idea. A lot of times public bathrooms will have a disposable, flushable, parchment paper that can be placed on the seat and a flap leads down to the water. If you were to have 4 of these flaps instead of 1 I think it would protect the bowl enough.

I had to look it up... Haha.

Have you tried a space toilet?

And I know you mentioned a feeding tube, can they add fiber in your diet somehow? I used to get similar issues while not eating enough fiber.

Any forums of people with similar conditions that could recommend solutions?

Best of luck.

Props for keeping your sense of humor, dude.

Survivor of sinus cancer here. Not a fun experience but it worked. May you find NED and remain that way. Godspeed.

Best of luck.

In a former flat I had a plumber over, we got to chat a bit. He said that in they often get called to subsidized housing, as the amount of water used in toilets there is often set to a low setting in order to save money.

He was a bit more colorful, but in essence he said: With two liters of water you are not going to move 1kg feces far enough down the pipe, so it starts piling up. That's the reason why they get called there more often.

So no matter how you coat it (pun intended), what problem are you trying to solve? Also re-applying the lubricant after 500 flushes means I have to re-apply it after around four months with two people in a household using the toilet twice per day. With kids or more room mates, even more often? I think I'd pass and rather clean the toilet properly.

If you're only using the toilet twice per day, I suggest drinking more water :) https://www.healthline.com/health/how-often-should-you-pee

But maybe you mean only flushing twice per day, despite using it more frequently, in order to save water? That would beg the question of how this coating material would hold up when subjected for hours per day to the "toilet environment" you produce vs. a clean water environment.

Yes, you are right. I should drink more water, but there is also another factor: Going to toilet at work saves water at home and is work time.

I learned that from a former colleague when I worked as a gardener

I think I'd like to know how this does without the second layer. Reapplying every 500 flushes doesn't seem practical. For a family of four and two toilets, if everyone goes four times a day, you're talking about reapplying every 2 months.

Permanent nanohairs sounds very ... permanent, if this doesn't work well without layer 2.

I'm also curious about durability on a car, with windshield wipers and all. How permanent is permanent?

I'll mention:

1) The price and quantity is a little bit off-putting. I'm not sure if that represents real costs (for many business models, the cost is a pennies, but the price goes way up to account for R&D, shipping, marketing, etc.). If this is expensive to produce, keep things as is. If it's dirt cheap, you may consider keeping price fixed, but notching up quantity a bit. If I can coat my whole car (rather than just windshield), or sink+toilet rather than just toilet, or even share with a friend, the economics become very different.

2) You really need online reviews. Few will risk a product like this unseen. Use Amazon or send review copies to someone.

Reapplying every 500 flushes doesn't seem practical. For a family of four and two toilets, if everyone goes four times a day, you're talking about reapplying every 2 months.

I think it depends on how exactly one applies it. If it’s just pouring something from a bottle over the bowl, it is perfectly practical, as this is already what one usually does when cleaning the toilet.

Sounds promising but I personally need more info or at least certification on new products safety characteristics. I wont go into an alarmist list, but some materials "based on silicone" are problematic and some are flat out hazardous. Probably this one is not, but more info is due.

> silicone can be decomposed naturally in soil within 4-7 days. It breaks down in silica, water, and carbon dioxide.

So why doesn't the coating, if it is made of silicone, similarly degrade in 4-7 days?

One doesn't normally keep soil, with its rich microbial ecosystem, inside of their domestic toilet bowl.

One commonly puts something else with a rich microbial ecosystem in it on a regular basis.

Yes. However, it's "something else", meaning that the ecosystem is dramatically different. Furthermore, the majority of that ecosystem should be evacuated on a regular basis. E.g. bury an apple in soil during humid warm weather, and a week later it may be substantially decomposed; float it in a regular toilet bowl and it will recognizably still be an apple.

Will the coating break down in a Septic tank?

My parents use roof water, which is a limited supply so this product would be a great help, but they would be sceptical of any product that could harm the microbiology of the septic tank or that could harm the soil from the overflow.

I imagine they would prefer some sort of scientific facts rather than just marketing blurb (they are quite biologically geeky!)

Is this similar to LiquiGlide? https://www.fastcompany.com/1679878/mits-freaky-non-stick-co...

If not, what are the pros and cons of using LiquiGlide in a toilet vs. yours?

If it's not harmful to sea life then a great potential market for this would be marine toilets. They all use extremely small amounts of water (especially the freshwater ones) and skid marks are always a problem. Boaters are also used to maintaining things like coating.

Smaller market but a good niche to start and spread from.

Why do salt water marine toilets use small amounts of water? It seems like that's a resource that is very easy to acquire.

The water and waste are pumped into a holding tank that needs to be emptied. You can empty it into the ocean if you are 3 miles off shore. Most people stay close to shore, so need to use pump out facilities to empty their holding tank. These are often free but not always, and from my understanding are not entirely pleasant to use.

Typical holding tank volume is 20-30 gallons. This is maybe enough for a week? We have a composting head so I'm not sure. Solid waste goes in a dumpster once a month and I think most people end up "peeing in the water". Which is technically illegal and some people think is bad, some don't.

Especially with plastic plumbing

If you clean the toilet with soap and a brush will it remove either the hairs or lubricant?

Edit: and bleach?

I think it is a brilliant product if it works as explained will sell at the price you have set. I will buy some.

I think a little bit of silicone is a smart trade off to save a lot of toilet-cleaning chemicals and compared to a toilet brush this is an order of magnitude better.

It would be interesting to know how many hacker-news users actually clean a toilet regularly. I'm guessing not many if any but that is an outrageous assumption. I know you will still have to clean the toilet after a spotLESS application but it will be easier and use less detergent.

Does the silicone lubricant have to come in a spray application or could you license spotLESS lubricant to the likes of Toilet-Duck to incorporate into toilet cleaners? If councils treated their sewers with the nanohair layer would the silicone lubricant floating past keep it lubricated.

It's a shame that the swoosh logo is already taken.

Awesome product and its good to see that price is kept affordable. Many comments here don't seem to appreciate the use case (public toilets) in places with high footfalls and high density (basically every public place in India).

Interesting approach back at my first job in Hydrodynamics research BHRA (Now Bhr Group ) in the early 80's

I shared an office with an engineer who's got assigned to research the efficacy of toilets - we had some interesting brainstorming sessions on how to solve some of the experimental problems.

I even started to look at using neural nets to use image recognition to measure how efficient a design was, but as the base hardware cost was over £250,000 that went nowhere, a pity but it would have taken my career in a different direction

How did you test the product during development? Did you have to take a shit on it after every iteration or did you have some kind of replica shit that could be used?

This may be a little broad of a question, but: Why is this being commercialized at all? The linked article makes a lot of noise about benefits for the developing world but making the coating tool dependent on the profit motive will naturally target those with existing money - the developed world. I'm just having a hard time squaring this particular circle.

This seems similar to SLIPS: https://wyss.harvard.edu/technology/slips-slippery-liquid-in...

How do LESS and SLIPS compare?

Is the coating food-safe without the lubricant? I have wanted a superhydrophobic+superoligophobic coating for dishes since I learned of the existence of such nanocoatings, but I haven't seen any that are durable and/or regarded as food safe.

Have you tried looking into applications with training toilets for kids. The clean up on those things is horrible.

So what about something like marble countertops?


500 flushes is less than a year for a toilet used twice a day (say before and after bed), I hope that coating is cheap, easy to apply, and doesn't create substantial pollution either as it is created or used.

I hope the sewer system doesn't need to just add water as a result.

Toilet water use doesn't seem like a big enough contributor to the problem that it's much use optimizing it in most places. But there are probably some where water is locally scarce and it makes sense.

I tend to agree, but I (and maybe you) live in the Great Lakes region where water is abundant and cheap. Optimizing water use just doesn't seem worth it.

But I can totally see this coating helping in regions like India, who have a real problem with open-air defecation.

I do live near the great lakes, but my comment about not worth optimizing is really just that as a percentage of global water usage toilets are tiny (compared to agricultural and industrial. Agricultural is 80-90% in the states for instance). Optimization only really makes much sense where locally that is false.

There are definitely plenty of deserts in the world though, so it's not much of a nitpick.

> Agricultural is 80-90% in the states for instance

Actually, irrigation uses less than 40% of water in the US. The largest use is thermoelectric power generation. [0]

[0] https://pubs.usgs.gov/fs/2018/3035/fs20183035.pdf

The majority of that water is surface water - that is only used for consumption if there is no suitable groundwater reservoir, and it is returned. So the environmental impact is less that irrigation as that removes the water from the source.

Interesting. It’s not like water used for thermoelectric cooling becomes compromised. In many cases don’t they just return it directly to the supply after it cools down?


I think you're deliberately misrepresenting what I meant.

The current PM of India campaigned on a "Clean India" effort to tackle open-air defecation by building millions of toilets. Now, you can argue the efficacy of this effort, but arguably, the entire scheme requires adequate means to actually flush the toilets, which requires water, which requires infrastructure. All I meant is that efforts to minimize the amount of water required (i.e. the coating in the article) could be helpful here.

Another place where this can be helpful is in areas that aren't covered by sewage infrastructures, like houses that are on septic tanks, or campgrounds/parks with outhouses.

I'm not an expert on this matter, I'm just suggesting that I can see how it might be helpful.

> the entire scheme requires adequate means to actually flush the toilets, which requires water

The vast, vast majority of these toilets are basically just holes in the ground. They do not flush.

Exactly. In our village, it was a latrine. We were lucky enough to have ceramic ones.

When I first encountered this as a 4 year old, I was so disgusted with the idea of squatting over a latrine that my parents had to have a Western toilet installed in our house in the village. When I returned at 10 years old, I was more amenable to the idea.

Every time you had to go, you had to fill a bucket of water from the well, and carry it with you to the outhouse. Then you’d squat over the latrine, do your deed, and then use a cup (a lota) to pour water over your backside, using the other hand to help rinse. Heaven forbid you had to do all of this at night.

When I got back to Canada, it was the toilet that I missed the most. Now, I appreciate the sheer convenience and modern marvel that is modern plumbing and sewage.

Composting toilets seem much better suited for locations with scarce water, or scarce water infrastructure.

The additional maintainance maybe doesn’t worth it for homes, but clean toilets would be important in commercial space.

You only use toilet twice a day? Keep in mind you need to flush after pee too.

> Keep in mind you need to flush after pee too.

When you only have restricted water, you shouldn't flush after peeing. There's even a saying to help conserve water this way:

"If it's yellow, let it mellow".

you left off the ending: "if it's brown, flush it down".

I was being conservative, since the number of times any given toilet is used per day is pretty variable and the conservative result was already enough to say "this needs to be re-applied frequently".

Sounds like it has to be applied to a dry toilet, further complicating the reapplication process.

As someone who lives in an area without water and sewerage services anything to reduce water consumption is a bonus, especially if it's biodegradable.

Sure, a flush is only 3-4 litres but that could make the difference in a dry summer.

> When we put that coating on a toilet in the lab and dump synthetic fecal matter on it

This reminds me of a documentary about toilets, and one factoid was that American toilets were much worse at flushing than Japanese ones, and would block more frequently, and it turns out that American ones were tested with a small standardized rubber ball, while Japanese ones with the real deal, including big productions.

I watched a video from This Old House where they toured a toilet factory. They used Miso paste in a condom to simulate fecal matter.

"7 links of miso"... I remember that every time I buy sausage links. Gross haha.

It’s interesting!


Why don't we use grey water to flush toilets? It can use water either from the bathroom sink or shower.

Honestly, I do. I've placed a bucket in the sink to capture waste water from washing hands, which is then reused for flushing the toilet after depositing... liquid contents in it. It saves a bit off the water bill and also made me realize just how much water I use up when washing hands...

Of course I hide the bucket when guests come, it's too weird a thing - but in all honesty, I've wished many times for a system for capturing sink & shower water in a tank, for use in toilet. The standard practice is inefficient.

EDIT: I didn't know the term "greywater" before, and after reading https://en.wikipedia.org/wiki/Greywater I'm having second thoughts about my scheme. If the city is actually treating greywater and water from toilets separately, then I guess it makes sense to let the sink water drain. But then again, that's a huge if. I'll need to take a closer look at my indoor plumbing and read up on the water treatment scheme in my area.

As of now, very few buildings have separate grey and black water plumbing. In the event that you did have separate plumbing in the building, you would need separate plumbing in the street as well.

Unless you live in a very water constrained area, it's pretty unlikely. In the US, plumbing for reclaimed water is available in some areas (purple pipes), and seems like an easier intervention, it's often used for landscape irrigation, which has easily accessible plumbing to retrofit. It can be used for toilet flushing as well, if that is plumbed separately from other fixtures in the building.

Can you irrigate with water that has detergents in it though?

Yes, depending on the detergent content. Reclaimed water is usually water that's been treated for pathogens at the treatment plant, but hasn't had been through all of the post-treatment cleansing required before discharging into waterways.

It's exceedingly unlikely your American home is keeping graywater separate from blackwater. If it were, you would know, it would have been mentioned as it's quite exceptional.

California not long ago changed its laws regarding graywater handling in response to the sustained droughts. Now residents are permitted to divert graywater themselves for other purposes like irrigation and gardening. So it's become a little more common to find diverted graywater systems in response to this change, but they're often ad-hoc diy setups in drought-stricken regions.

You're right though, showers and laundry are huge wastes of water, at least relative to residential water use. Unlike toilets, they're also much harder/impossible problems to solve without the voluminous use of clean water. With toilets there are options like composting and incinerating, and in places with ocean access seawater can be used for flushing. Bathing and laundry don't really have alternatives.

Here in Belgium it is mandatory (for quite some years) with every new building development to install a tank capturing rain water from the roof. This water must be used for flushing toilets and you typically also use it to water the garden, wash your car, etc. With some extra (carbon) filters people also use it for their washing machine.

I have a 10000L tank which is more than sufficient for a household of 4 and some garden. The minimum size is calculated based on your roof surface but normally people install a bigger tank. The extra cost for a few 1000L more really isn't that much and it can save you the cost of a fallback system in case the tank runs dry.

The overflow of the tank goes to a separate sewage system that usually ends in a local stream. This way it doesn't dilute the actual grey/black water which, incidentally, makes a water treatment plant more effective (or so they say). It also allows the water to infiltrate into the ground and there's less risk of flooding the streets during a downpour. At least, this is the theory. Work is still very much in progress to split the sewage systems but we're getting there.

You can put a small sump pump with a pressure switch in the bucket, and an overflow setup back into the normal drain. This way when the toilet flushes, the sump will kick on and fill the toilet and keep pressure on the water line feeding it. Any excess sink water will overflow out the upper hose on the bucket and go into the normal drain.

Correct me if I'm wrong, but couldn't you just have the one output from the pump going to the toilet tank? Then if the overflow switch triggers the sump pump, it'll overfill the toilet tank, which will drain into the toilet bowl, and down the drain... right?

I’ve heard that newer houses (this was over 15 years ago though) here in Germany often use shower/bath water for the toilet.

Probably because it requires extra plumbing, not to mention a storage tank. And most places don't have a fresh water shortage.

I've seen where the tank top is a handwashing station. There is a faucet on top and a small basin in the tank top, when you flush, the inlet is connected to the faucet. You wash and the soap water goes into the tank for use on the next flush.

I understand Hong Kong uses seawater to flush toilets.

The chlorination process is simple: just pass some current through the salt and voila, chlorine.

Japan has this... a common design is to have the bathroom sink drain directly into the toilet's water reservoir, so the grey water is used for the next flush. No changes to plumbing needed, since it's all built into the fixtures.

Admittedly, there is a bit of a psychological hurdle to washing your hands in the toilet, even though the water is isolated and perfectly clean. (This could be solved through clever plumbing, to separate the two fixtures.)

Example: https://www.reddit.com/r/mildlyinteresting/comments/9rabuk/t...

If your hands are particularly dirty (a very possible use case for a sink) do you flush after? Genuinely curious.


The reason so many 'amazing' idea never take off in houses and why cookie cutter housing rules.

There are big regulations, if you cross the piping you could theoretically contaminate the streets or larger water supply.

You now have two water systems in a house. Plumbing is not cheap, having two is more $.

You'll need a pump and holding tank, a place to run the pump and holding tank. It'll might me loud and can break down, will fail in blackouts. Can the tank get legionnaires disease?

The cost of additional plumbing is not small. Also, what is the source of grey water? If it's your house drainage, when you rinse chicken blood or poop or one of the other many nasty things people rinse down the drain, now it sits in your tank for an undermined period of time?

Or like my parents, use a well's water (not potable) for their toilets. That required a small dedicated tank, a small pump to a well, and dedicated pipes for the toilets. Potable water is for all other needs (sink, shower, etc).

I came here just to say that - if memory serves - this was mentioned in The Mote in God's Eye by Niven & Pournelle: humans have contacted an alien race, and the aliens suggest some improvements to the human technology on display on the spaceship. Among these, a "frictionless material" which one of the human engineers points out "will save lots of water on arid planets and also on the spaceships themselves".

(During the exchange with the aliens who live there, one

What is this stuff made from? I hope they think of the fish, that's all.

Raw sewage probably isn’t that great for fish either.

Raw sewage is well known to decompose in the environment into harmless things. Unlike the majority of chemicals we invented in the last 100 years or so.

Errr.....no? Human waste in water is a major cause of disease. Sure, a turd or two won't be a problem. And sure, it'll decompose. But all kinds of pathogens remain. There are billions of people, and as the eponymous book says: everyone poops.

People have been pooping for millions of years without filling our oceans with poop. We have been creating new chemicals for a hundred years and have created a huge waste problem. The last time pooping had a big impact on the global ecosystem was during the Great Oxygenation Event, afaik.

Yeah, it may be a concern in terms of extra costs in sewage treatment.

> The researchers also predict the coating could last for about 500 flushes in a conventional toilet before a reapplication of the lubricant layer is needed.

It's a neat idea - especially the fact the bowl remains white, unlike a coating of PTFE or similar.

I wonder if it's an idea they can develop further into a permanent coating?

Yeah, 500 flushes is not really very many. I live alone and I reckon I flush the loo at least three times a day, which would mean the coating needed reapplying every six months. If you're a family then it's probably heading down towards every three months. If this spray can be re-applied by the end-user and isn't too expensive that's annoying but just about OK I guess. If it needs a technician visit and/or it's an expensive coating then it's not practical. An order of magnitude more flushes between recoatings would definitely be better...

...which is strange, since PTFE is naturally white. I think we've become used to seeing it on silver and grey frying pans.

But that said, what's wrong with a dark-colored toilet?

Merely that a coating that retains total choice in colours is more flexible than one that limits the range of colours possible.

And presumably that's part of the contribution here - a nonstick toilet that doesn't look like the ones you get on planes and trains already.

Also, the current fashion in my country is for white toilets - you go to a bathroom showroom, ~95% of what's on display will be white. A design that doesn't require a change in fashions is simpler than one that needs tastes to change.

It would get really dirty before you realized it. With a white toilet, it's really obvious when it needs to be cleaned.

All colors are wrong. So that you can properly see a clog, the toilet must be clear glass.

More chemical waste in our water system. There's nothing wrong with the amount of water we currently use to flush our toilets. Now, there's something to be said for a cleaner flush, but another solution to that problem - with many other benefits - is to consume more fiber

> "There's nothing wrong with the amount of water we currently use to flush our toilets."

That depends entirely on where you live. Depending on the local situation, you might have almost no fresh water, way too much fresh water, or just the right amount of it. In these sort of conversations people often seem to forget that their local conditions are not universal.

The US toilet design with the huge bowl of water is incredibly wasteful and inefficient and just not that good, compared to toilets in EU/AU/JP.

I find a toilet brush works just fine..

Less water in the sewer is only going to create problems for the flow rates further down the line, Possibly blockages in the pipe on your property.

and i would prefer not to put silicone (if that is what they are using as it is "like hair conditioner") as some silicones can take 400 to 500 years to break down

It seems like there was something similar a few years back that got a lot of press as solving the ketchup-adhering-to-the-bottle-problem


Are we sure this is not a step backwards? We woild benuaing.less water, but filling our lakes with lubricant?

From a comment above from the developer, it seems this stuff (particularly the second coating) is akin to hair conditioner.

Since it seems like HN are just Luddites afraid of something new or don't understand the product, lets spell it out.

Cleaning a toilet sucks, this product will sell well if it works as claims and makes it easier. They will get $, you will not.

Cleaning public buildings is a huge cost that takes manual labour, if this product has a good price point and works as they say, it will save $100 of millions yearly.

No one in the real world actually cares about saving water in the home and being afraid of new things is boring.

The only question is "The researchers also predict the coating could last for about 500 flushes " In the past the issue stopping these products being everywhere has been the fact they wear out quickly when abraised.

Unpopular opinion warning!

Getting people to save water is one of the simplest things in the world!

Water is the cheapest material that people have access to. It is so cheap it has been devalued to the extreme. Fill a backyard pool? That'll be less than $100...

Raise the price a little bit, all of a sudden people will use less water, they won't even notice any effect and have the same quality of life.

Framing a scientific breakthrough as "saving money on water" is ridiculous. We already have a simple solution that works.

It should be tiered, which it is but not to the degree that it sound.

But really the problem is businesses and especially farmers growing non-essential crops, especially in California. The drought we experienced over the last several years was mainly exacerbated by farmers who were growing non-essential but expensive crops like almonds. I would rather the almond farmers go bankrupt than have them spend 1 gallon per almond in water.

Businesses should pay more for water, and if it causes inflation in prices, maybe that's okay if the cost of almonds double. The amount of money that Nestle pays to bottle water for free is far too low. If it drives bottled water out of service because the costs are too high, I also think that's okay.

Almonds are a red herring where California crops are concerned.

Around half of California's agricultural water use goes to alfalfa, a fodder crop which may be grown anywhere.

Israel uses subsurface drip irrigation to grow almonds, which is more than ten times as efficient as California's flood irrigation system.

The problem is not inherent to the crop; it is political, and downstream (pun intended) of California's approach to water rights.

> people will use less water, they won't even notice any effect

These are mutually exclusive statements in this context.

"any effect on their quality of life" - what I meant ...

now does being motivated to fix a leaky toilet that otherwise you wouldn't have bothered to do count as a quality of life decrease?

How many people have leaky toilette that they can easily fix to lower the impact of higher fees?


How many people are living on the margins and that extra $10 represents the last meal to get to the end of the month?

You are derailing the discussion - we were talking about the practicality of covering toilets with a slick substance while touting the water-saving potential of said act. To which I stated that instead of covering the toilet with that slick substance we'd save more if we made water a little more costly to dissuade people from wasting water on a large scale.

Now all of a sudden that got turned into some poor family in an undisclosed location not being able to feed themselves because water is too expensive ... quite the logical hyperjump ...

No, you dismissed a techno-industrial solution by proposing to raise water prices instead.

I happen to agree that techno-industrial solutions are band-aids best addressed with social and self-growth.

However, your proposed method of social change is more complicated that you let on. People on the margins are not some hypothetical "poor family in an undisclosed location not being able to feed themselves because water is too expensive"

They are literally the set of marginal individuals, marginal as defined in Econ 201 (marginal rates, marginal profits ect). That is people who are not so poor that they are already skipping meals (or on food stamps), but they cannot save an extra $10/month either. At the end of the month the net change in their net value is zero.

If we expand the set to include people and families who are in the red or in the black by about $50/month, that includes millions of Americans. And, for these people, $10/month of added water bills hurts. A lot.

That's not to say raising prices is a bad idea. I happen to agree with it. I also happen to agree with raising gas taxes, levying road tolls, and, in general, attaching the externality cost to the first user as much as possible (I.e. the gas tax to transport the tomato you eat is paid by the shipping company whose job it is to find economic ways to ship).

However, I'm under no delusions that this tax scheme is regressive. Should the repressiveness be addressed or dismissed is another question.

> Water is the cheapest material that people have access to.

You don't live in the American South. I actually suspect you live near one of the Great Lakes where the water is dirt cheap. My water bill is higher than my Internet bill.

Something I have wondered a couple times when this comes up: When people say "Water bill", do they mean solely water, or water + sewer?

Where I live, the two are bundled, and the total bill is also higher than our internet bill. (~$100 for water vs $75 for internet)

I live in Iowa, which doesn't have Great Lakes levels of water lying around, but we also have no shortage of the stuff.

Yes, they're often combined, on the basis that it's easier to measure water usage than sewer usage and the latter is presumed to be proportional to the former.

So when people say "my water bill is higher than $X", do they mean the combined bill? Does the town I live in just have abnormally high water prices for an area without water scarcity, or is water just artificially cheap in other places?

Regarding the former - Yes. It's basically something like this:

line 1 - Water usage = X line 2 - Sewage usage = X * modifier

My monthly water usage is usually something like $20 worth, but my "water bill" is usually around $60-$65 when combining water + sewage (2 adults, $ = USD).

Some people (those who own wells) don't have real "water bills" at all and are actually referring to a portion of their electric bill corresponding to the well pump usage when they say "water bill". (Depending on well depth and usage patterns, this may or may not be a significant portion of the power bill.)

We had a well growing up, and I think we always just considered the water free. Though we did have a water softener, so I suppose there was the cost of salt for that. Similar to water heating though, I think we didn't really factor that into the cost of the water.

The depth of the well is a huge factor, generally the deeper the well the harder it is to pump water out of it. There is also the matter of how fast the well will replentish. Shallow wells into unconfined aquifers in regions with plenty of rainfall are probably the best sort of wells. Those sort of wells get replenished every year (climate permitting.) On the other hand with fossil aquifers you're draining a finite amount of water that won't replenish in human timescales, if at all.

So in some regions pulling water from wells will be perfectly sustainable and essentially free, while in others it's unsustainable and expensive.

Works great until the farmer next door sucks your shallow well dry with his new irrigation system.

As I've been saying, the matter of fresh water is very local. You may or may not be near such a farmer, and such a farmer may or may not be capable of pumping that much fresh water out of the ground in the first place. In some places that's a real problem while in others it isn't.

I don’t mean this judgmentally, but how much water do you use? The bulk of residential water use tends to be for landscaping, in particular watering lawns. When my city raised rates for excess water usage, all of the homeowners complained, even though they require vastly more water infrastructure and end up using a lot more water for their lawns.

Water should be cheap, it's less expensive overall that society dealing with poor water sources (healthcare, developmental). There should be a two tier price system. Cheap up to a threshold, then expensive beyond that, like with mobile internet.

And even then, tech to reduce waste is great and should be celebrated and is not mutually exclusive.

I think saying here is toilet where your poop does not smear is a much better slogan.

As a general rule for necessities, if you want it to be cheap enough for the poor to be able to comfortably use what they need it has to be cheap enough for the rich to waste it. For water specifically, Private use is a drop in the bucket compared to commercial and agricultural use.

@birgitt: Instead of a labor intensive process of spraying and paper or cloth, could you not include the lubricant in a separate reservoir and apply a bit with each flush, avoiding the need for a manual process? Or perhaps have an automatic cycle where the bowl drains, the lubricant is applied, and then water is supplied to refill the bowl after a period of time has elapsed (if necessary)?

It seems manual application is likely to slow adoption IMHO. If automated, seems like a slam dunk for heavy use/commercial/public applications though.

Manual application is gross, but adoption could be quick if it is focused on companies that use janitorial services...

Honestly how many Hacker News readers read this story and thought about ordering the product and having their weekly cleaning person be in charge of applying this even monthly in their homes?

Or just float a thin layer on top of the water that will encapsulate ...ahem...the capsule.

I cannot wait — I cannot, cannot wait — for my cat to _finally_ fall in

I've got a wheel of cheese with my name on it.

Reminds me of an old plumbing trick: got a really stuck toilet? Pour a little dish soap into the bowl. It makes everything slippery so dislodging debris is much easier.

Unfortunately I recently gained the experience to confirm that this does not work. It wasn’t even “really” stuck and yet the dish soap did nothing (nor chemical drain unblockers), only the good old plunger did the trick.

I think this works for hair clogs too, IIRC.

All of the money people save on their water bill can now be put aside for their annual call to the plumber as you'll likely end up clogging your pipes. Not enough water in every flush means you'll end up with a blockage at some point because the feces was never irrigated out of your pipes to the street.

Large, old cities already have problems with their waste canals clogging because modern toilets and showers use too little water. I wonder how this can be solved in the future, perhaps by coating the canal as well?

Surprisingly, at the same time they often outlaw channeling rainwater (coming down from the roof) into the wastewater system, although that seems to be a solution to several problems at once.

Rainwater often causes the opposite extreme with the same result, i.e. canals overflowing with water (rain = a lot of water in a very short time), which means they're blocked too.

There are solutions that help you save water by requiring you to flush only when taking a dump (by preventing pee from smelling and hiding it). I don't remember the exact products.

This kind of thing seems a hassle to do manually. As a feature on a smart toilet though...

Why not other applications? Boat hulls, water slides, dishes, cookware?

Are there existing examples of commercial (ahem) goophobic coatings?

Haven't airplane toilets been doing this for a long time?

PSA: Do NOT put this stuff on the toilet seat.

How satisfying to watch that video....

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