ohthanks's comments

The vast majority of these 400 heat deaths have nothing to do with the power grid. They are people living outdoors, roofers, elderly, etc. When the temps hit 105+ for long periods there are bound to be people who don't have access to AC or overexert themselves outdoors.

They don't boost the feed pressure, just isolate the output permeate line from the back pressure of the storage tank. Instead of the membrane output pushing against the increasing pressure of tank as it fills (decreasing output) it produces into a void in pump body which the pump periodically pushes into the tank from spring mechanism wound by the output waste water.

They work pretty well to reduce waste but do add complexity to what is already a somewhat complicated device under the sink. They will also create bad TDS creep if used without an auto-shutoff valve installed in the RO.

I have built and sold RO systems for 20+ years. It's a weird industry and there are some competing desires in place. In general it's kind of a mess and it's difficult for consumers to navigate.

You can build your own system for less than $150 from cheap parts on ebay. You can buy a branded unit at a big box or amazon for $150-250. Or a "health" branded version for $300-800. Or have an installer put whatever they sell in for $500-1500.

My experience is that you will get nearly identical water quality from each of those systems. There are different options and some fine details but the fundamentals haven't changed in decades and you are paying for some collection of service, parts quality, future replacement costs, marketing and snake oil.

NSF certification is good, it will rule out products that are flat out harmful. I have seen lots of cheap filters with fake certifications and there are many great filters that it don't carry certification. NSF material and safety cert (51) is a good one to look for, beyond that is has more to do with how the product will be sold and marketed than a real measure of performance.

$250-500 is probably the right price range for a diy install unit. Check for replacement part costs, buy something with standard components and cartridge sizes. Learn how it works, change the filters on time and expect to replace components every now and then.

The articles state higher levels in bottled water treated with RO but there are many stages of treatment and delivery involved in industrial scale bottled water production. Unclear if RO itself is the underlying cause.

RO membranes are tight enough and should effectively remove all microplastics from the output water. On a consumer RO system the water will still pass through a few final treatment stages and a few feet of plastic tubing before getting to your glass.

Very possible some additional plastic is being introduced in the post membrane stages and delivery but my assumption is that a point of use RO system is going to reasonably effective.

There is some chance the manufacturers are omitting the fact that all membranes are bleeding microplastics during use. At the moment I don't think we have enough evidence to say they are and most testing has shown them to be effective as a removal method.

ZeroWater uses a mixed bed ion exchange resin (anion and cation) to attract and hold dissolved ionized solids. Mixed bed resin is very effective and will remove nearly 100% of dissolved solid content which will includes all heavy metals.

The downside of mixed bed resins is that they are not selective and water with high dissolved content (TDS) will deplete the resin at very fast rate. Price per gallon is comparable to bottled water with moderate to high TDS. They are simple and very effective as long as the filter is replaced as needed.

There can be downsides to the permeate pumps, but not many.

Installed with a standard hydraulic shut off valve (ASO) you won't see any issues but you won't get much in the way of improved storage pressure. You will just see improved product/waste ratio as the pump negates the back pressure from the tank. The downsides are the periodic thumping noise and the added complexity of the extra tubings and fittings.

Installed without an ASO valve the permeate pumps will cause some TDS creep and bleed high TDS product water into the storage tank each time the system stops and starts. This will mix with the low TDS product water and raise the average up somewhat. The amount will vary on usage behavior but it's a noticeable TDS bump for most users.

I sell residential RO systems. Industry wide the tubing is typically LDPE and the housings/fittings are mostly polypropylene. There is no real practical way to build a residential RO system without using these materials.

It's a trade off between different types of plastic / chemical exposure. Not really ideal but I suspect nearly all sources of treated water will have traveled through a similar amount of plastic to get to you.

Copper is avoided on RO systems because the post membrane water typically drops 1-3 points in PH and will slowly corrode and leech copper into the treated water. All post membrane fittings and tubing should be plastic/stainless, cheap brass fittings with high lead content are the biggest concern. This can be resolved with post membrane PH amendment but you then create a failure point that can cause heavy metal exposure or leaks if it isn't maintained.

You could build a system with steel housings and braided stainless hose but the size/weight and cost are not practical.

This is not a consumer product at all. I don't know how useful it will be but it's designed to be development tool for early art direction visualization.

Even for 2d visualization it could be very useful if you could drop images into your website mockup files and have it intelligently apply color palette and texture information to your existing content.

It won't look good, but it might look good enough to save you from having to manually tweak the design 20-30 times to explore a range of styles.

I think it's actually pretty hard to tell much from the membrane itself, my understanding is that most of the process is based in the membrane preferring the smaller water-only molecules and allowing the waste run off to carry away anything else. So they shouldn't really be catching much in the element.

They fail either from the chlorine degrading the membrane film which will start allowing larger dissolved solids through (your TDS will increase) or by having the pores scale and plug over time which will slowly decrease the output.

You can remineralize with limestone post-filtration.

Or eat food.

I didn't mean that a custom domain is an indicator. Just that they go to the trouble to register throwaways for this use and it isn't limited to just free email services.

I periodically deal with recurring fraud from what seems to be a pretty organized network.

- Orders are placed with stolen credentials with correct billing info that matches AVS.

- Shipto address are located near billing info, typically in the same state/metro area.

- They are often rural addresses, trailer parks, what appear to be rent houses that may be empty.

- Phone number provided has correct area code and rings a call center that has stolen billing info available and will confirm billing address order details verbally.

- Ip is geolocated at/near the billing info area via a proxy.

- Email addresses are often setup on custom domains.

We catch them, but only because they don't vary the pattern much and we know what to look for. I don't know how fraud tools would be able to effectively filter in these cases without a lot of false positives.

There are no official treatment recommendations for PFNA, PFOA, PFOS that I know of but they can be treated with activated carbon, RO membranes or some combination. GAC seems to be pretty effective and you could feel pretty safe with a Brita filter, a multi-stage undersink system or a large whole house filter.

The issue with chemicals like these and treatment is that without extensive testing there isn't much information about breakthrough rate and contact time and the relationship, so repeated testing is really the only way to know when you need to change media.

Manufacture cartridge change recommendations generally are pegged to chlorine removal only, so a filter may deplete it's PFOA removal potential in a 1/10 the recommended change interval.

This is totally correct. It is also not very applicable to drinking water & whole house systems that homeowners are interested in.

There are carbon cartridges with ion-exchanges resins blended into the block that seem to be effective for lead removal at low flow rates. They tend to have lower flow-rates and capacity than is ideal.

You will for sure, I actually like it but not everyone does. You can remineralize and change the taste without too much trouble. I would avoid any other claims made for that process but it does usually improve the taste. Straight RO water is not great for coffee or tea as well.

Carbon filtration will not remove dissolved solids (lead, heavy metals) without added ion-exchange resins. RO is generally the most effective broad spectrum treatment method for drinking water.

The mineral issue is pretty much bunk, if the lack of trace minerals in your water is a concern you need to see a doctor. Food is your body's preferred source of minerals, you have to drink a lot to have much effect on your daily mineral intake.

The waste water is real, 4 to 1 is about average, it can be improved but it's pretty unavoidable in the process. They are water using appliances, we use 20-40 gallons of water to wash a load of clothes and most people don't think twice about it.

I can't vouch for any the actual content he is posting, but I can very confidently confirm this is his blog.

http://www.kickstarter.com/projects/zioneyez/eyeztm-by-zione... seems like a pretty clear example of this. Backers are actually starting a separate forum to discuss legal action. Doesn't seem to be any sort of recourse via kickstarter.

pretty sure that is my friend Ben Barry, http://www.designforfun.com/

been doing some very excellent design work for fb over the past few years.