Water Maker options

[FWT]

The things you learn on this forum is amazing. Water so purified it is corrosive and unhealthy.

People add a bit of chlorine to water taken aboard. What we need is some standard dose of "stuff" to add to water made / filtered aboard?

 

[GoneDiving]

Following

 

[Simi 60]

Very good article!


The only thing I see as a challenge is that water from a marine RO system is generally between 140 and about 200 PPM TDS, and the article seems to define low mineral content water as <50 PPM.

I might pick up some "mineral powder" on amazon just to hedge my bet.

Surely there are enough minerals in a decent diet, you know, fresh veges, meat , legumes, fish etc.
Its not like water is the only thing to enter our systems.

 

[Simi 60]

RO permeate has a relatively low pH and drops about 1 point from the feedwater pH. Average seawater is around 7.2 so permeate will be around 6.2. RO permeate has little to no alkalinity or hardness. Combined with dissolved oxygen this makes the permeate unstable and aggressive. Water wants to balance and become stable so it will leach metals from any source it finds to do so. That means any metal pipe, pumps, hot water heaters especially, washing machine, dish washer, etc. will be slowly corroded over time.

Interesting
We have a 240v pressure pump to supply water on board.
The pump housing is cast iron as is common on well pumps and every morning, the first few litres of water are brown, rust coloured and wasted.
The supplier of the pump reckons it should have stabilised itself several months ago yet the issue persists

Maybe this be the problem?

 

[HTurner]

There are such things as Vitamin and Mineral supplements, that one can take daily.

 

[Hippocampus]

Unless you have a known deficiency such as pernicious anemia (B12 deficiency) there’s no known benefit from taking vitamin supplements. In fact excess vitamin supplements can cause disease such as pseudotumor cerebri ( intracranial hypertension) Need for mineral supplements is dependent upon the nature of the water you drink. In the past some regions (parts of the mid west) had sufficiently low levels as to as to produce disease (I+ so goiter). However, this is now unusual. If you live on well water it’s cheap and easy to have it analyzed to see if you’re getting a good mix of minerals. Draw the water after all your filtering at the faucet not the pump head ‘cause that’s what’s you're ingesting.
It’s obvious Big does this stuff for a living and the situation with large, municipal systems is very different than the small units on boats. My understanding from my son in law is at least in the US domestic water supplies are closely regulated and monitored. More common issue is contamination of the aquifer. Even in my town in certain areas wells are not permitted. Defer to Big but wouldn’t think mineral supplements are commonly required or of benefit for dirt dwellers in the US. The WHO read seem to be more relevant to the world at large not 1st world nations

 

[twistedtree]

RO permeate has a relatively low pH and drops about 1 point from the feedwater pH. Average seawater is around 7.2 so permeate will be around 6.2. RO permeate has little to no alkalinity or hardness. Combined with dissolved oxygen this makes the permeate unstable and aggressive. Water wants to balance and become stable so it will leach metals from any source it finds to do so. That means any metal pipe, pumps, hot water heaters especially, washing machine, dish washer, etc. will be slowly corroded over time.

The Langlier Saturation Index (LSI) is a quick reference method for determining water corrosivity. A negative LSI is corrosive while a positive LSI is plating, meaning constituents in the water are coming out of solution and coating the metal surfaces stopping corrosion. Average SWRO has an LSI of around -1.2 which is very corrosive. On larger land based facilities we use Zinc Orthophospahte as one of the chemicals to reduce corrosion. The Zinc falls out of solution and plates the metal components with a zinc layer protecting it. To get SWRO permeate positive is a very difficult and constantly changing effort requiring at least 3 different post treatment chemicals, constant monitoring and adjustment. As feedwater chemistry changes with tide and rainfall so does the permeate and requirement for chemical adjustment.

I wrote a detailed paper on this subject back in the 90's. Ill try to find it and post. Sorry for the length but you asked...

Thanks. What's the best course of action for a boat owner? My HW tank manufacturer says to check the zincs more frequently. But I'm thinking that would help if it were an electrolytic corrosion, but not so much where the water itself is overly corrosive. True? Not true?

 

[Hippocampus]

Believe like my prior outbound Nordhavns have grp tanks so a non issue beyond your fittings. Most times now runs are plastic and pvc and most fittings plastics as well. We had some pitting on chromed endpoint fittings like faucets after 7 years which of course are easy to replace so did that. No issues elsewhere. Have seen some folks recondition their domestic water before the pressure pump(s) as close to the tank(s) as possible. Others do it at the watermaker’s product output which makes more sense to me. Given the absence of metal fittings at any junctions and grp tanks we didn’t but probably should have. That would impact what’s sitting in your hot water tank(s).

 

[TheBigWhit]

The things you learn on this forum is amazing. Water so purified it is corrosive and unhealthy.

People add a bit of chlorine to water taken aboard. What we need is some standard dose of "stuff" to add to water made / filtered aboard?

In my opinion, truly pure water (14 meg) is probably not wise to drink. I wouldn't suggest drinking distilled water long term although I will take a swig on occasion. Drinking SWRO permeate from a healthy RO unit is excellent and millions of folks do so every day without issue. You can find studies for and against it.

It is wise to sterilize tank water on boats once or twice a year if you only use RO water to fill it and provided it is sealed well. If there is any chance that crawling critters can access the tank then more frequent sterilizing is advisable. A shock chlorine level of 5 ppm free (fully reacted) is adequate.

Only other additive that may be wise is a passivation chemical(s) aka mineralizer. This is strictly to control metal system components. A mixture of Calcite and Corrosex is what we used for years in marine SWRO installations. This is easy and inexpensive to do. If interested I can explain.

 

[TheBigWhit]

Interesting
We have a 240v pressure pump to supply water on board.
The pump housing is cast iron as is common on well pumps and every morning, the first few litres of water are brown, rust coloured and wasted.
The supplier of the pump reckons it should have stabilised itself several months ago yet the issue persists

Maybe this be the problem?

Cast iron in SWRO permeate is sacrificial and will continue to leach and corrode. It may take years but it will eventually consume the pump internals. The only way to stop this corrosion is to plate it with zinc orthophosphate or a calcite/corrosex passivation filter. We always installed these filters on the RO permeate feeding the tank. Or you can go all plastic pumps and piping.

 

[TheBigWhit]

Unless you have a known deficiency such as pernicious anemia (B12 deficiency) there’s no known benefit from taking vitamin supplements. In fact excess vitamin supplements can cause disease such as pseudotumor cerebri ( intracranial hypertension) Need for mineral supplements is dependent upon the nature of the water you drink. In the past some regions (parts of the mid west) had sufficiently low levels as to as to produce disease (I+ so goiter). However, this is now unusual. If you live on well water it’s cheap and easy to have it analyzed to see if you’re getting a good mix of minerals. Draw the water after all your filtering at the faucet not the pump head ‘cause that’s what’s you're ingesting.
It’s obvious Big does this stuff for a living and the situation with large, municipal systems is very different than the small units on boats. My understanding from my son in law is at least in the US domestic water supplies are closely regulated and monitored. More common issue is contamination of the aquifer. Even in my town in certain areas wells are not permitted. Defer to Big but wouldn’t think mineral supplements are commonly required or of benefit for dirt dwellers in the US. The WHO read seem to be more relevant to the world at large not 1st world nations

Water is incredibly complex. Ground water and its contaminants is an entire world of study and new relationships are being discovered constantly. I was wrong earlier when I said no minerals are adsorbed by the body from drinking water. Obviously we can adsorb things from drinking water. What I should have said is "I don't believe our body can adsorb the majority of benificial minerals needed from the water we drink". There are studies that agree and disagree with my position.

Its true there are government agencies responsible for regulating public drinking water utilities. Many laws and people have created a complex web of burdens for public water providers. Yet we still have cases like Flint, MI lead poisoning and a multitude other yet undisclosed cases of poison in our taps. Government is the biggest violator of its own laws and regulations. Alum flocculation is a common municipal water clarifing chemical used by the ton in the US. The actual chemical is aluminum silicate. Aluminum is a well known source of Alzheimers. Why does the FedGov allow aluminum to be injected into our drinking water? Because its cheap and works and the downside contributes to a healthy pharmaceutical industry. I may be jaded but there are many other examples and I've seen a lot.

As to vitamin supplements, you can find studies and doctor opinions for and against. There are very poor quality (and down right unhealthy) vitamins (usually made in China) and there are high quality ones. I take only one brand made in the US. Recent lab tests and physical show my body chemistry is very good. Three close exposures to the Wuhan 19 and still negative tests. No colds or flu in over 15 years. If a subject is important to me I do my own research and make up my own mind after considering facts.

I greatly respect docs and have several close friends that are MD's. I listen to their opinions, do my own research, and always do what I determine is best. So far, so good...

 

[TheBigWhit]

Thanks. What's the best course of action for a boat owner? My HW tank manufacturer says to check the zincs more frequently. But I'm thinking that would help if it were an electrolytic corrosion, but not so much where the water itself is overly corrosive. True? Not true?

For every action there is a reaction. So we add ZOP or calcite/corrosex to passivate our corrosive RO water which plates the metal components and protects from corrosion. Smart. But this protective layer is insulating and that inhibits heat transfer in a HW tank. The heating elements are now protected from corrosion but you need more energy to heat the water. Compromises...

The zinc in the HW tank is good for electrolysis but does nothing for chemical corrosion.

What I do at my home and will do on my boat is install a passivation filter. Pay the extra in HW power consumption and DRAIN the bottom sludge off the HW tank at least twice/year. Allowing the heating element to sit in the corrosive sludge buildup at the bottom of the HW tank exacerbates corrosion. Then be willing to replace the HW tank every 7-10 years.

 

[TheBigWhit]

Sorry for these long posts folks but water is a complex subject...

 

[FWT]

Sorry for these long posts folks but water is a complex subject...

Don't apologize. Please continue. Following this conversation with interest

 

[twistedtree]

Sorry for these long posts folks but water is a complex subject...

Keep it coming.

What metals are most susceptible to corrosion? Thinking of my own plumbing system, I think it’s all plastic, stainless, or brass. Probably some copper too in the HW tank heat exchange coils for the engine and diesel heating. Not sure about valves etc inside appliances, but brass and plastic would be typical.

 

[Simi 60]

Cast iron in SWRO permeate is sacrificial and will continue to leach and corrode. It may take years but it will eventually consume the pump internals. The only way to stop this corrosion is to plate it with zinc orthophosphate or a calcite/corrosex passivation filter. We always installed these filters on the RO permeate feeding the tank. Or you can go all plastic pumps and piping.

Thanks for the reply

That filter, that's obviously before the pump?
Not cheap in Australia but cheaper than "another" pump
All plumbing is plastic but with a couple of brass bits and a copper Hot water tank
Who would have thought RO water was such a pita

Damn you watermaker, 5 years without and all good and now look what you've done

Add: "We always installed these filters on the RO permeate feeding the tank. "

So between watermaker and tank?
And that will solve the problem?

 

[Hippocampus]

Al was blamed for increased risk for AD. A lot of people threw out their Al cooking pans in response. Epidemiological study showed no significant relationship to tau protein amyloid plaques or twisted tubules/tangles. The more significant risks are basically the same as for atherosclerosis plus having the wrong parents. Any effect from Al is overwhelmed by those risk factors.
I’m not a hydrologist just a lowly neurologist. As said through out my postings -

Correlation does not prove causation

 

[TheBigWhit]

Keep it coming.

What metals are most susceptible to corrosion? Thinking of my own plumbing system, I think it’s all plastic, stainless, or brass. Probably some copper too in the HW tank heat exchange coils for the engine and diesel heating. Not sure about valves etc inside appliances, but brass and plastic would be typical.

Here is a chart that depicts metals hierarchy. The top is most sacrificial to bottom most noble. Combining different metals in the same solution can create other problems. Plastics are a great solution provided its material that wont itself leach. HDPE, PET, Delrin, Celcon and to a lesser extent PVC are good alternatives.

 

[Tusindtak]

Just reading this thread now. I researched TDS recommendations before buying a water maker for my boat. TDS is recommended by WHO at <50 ppm. My city water is 20 TDS in Seattle area, from mountain runoff. Maximum U.S. cities are above 800 TDS, which is very hard. My guess, based upon the reports, is that well water is harder than lake and surface water.
Dometic Spot Zero has a 15-25 TDS output. This reduces the need for toweling boat after wash down, saving about an hour and encouraging more washes. Occasionally towel dry, especially metal components.

 

[TheBigWhit]

Thanks for the reply

That filter, that's obviously before the pump?
Not cheap in Australia but cheaper than "another" pump
All plumbing is plastic but with a couple of brass bits and a copper Hot water tank
Who would have thought RO water was such a pita

Damn you watermaker, 5 years without and all good and now look what you've done

Add: "We always installed these filters on the RO permeate feeding the tank. "

So between watermaker and tank?
And that will solve the problem?

Yes sir, a passivation filter between RO and tank will help improve the situation provided all the chemical is not consumed before the pump. A steel watertank would likely plate out and consume 100% and leave the pump unprotected. You can only get so much calcite/corrosex into solution before the conductivity will exceed potable limits. Thats where zinc orthophosphate comes in. But its a PITA to apply requiring a tank, mixer and injection pump. Might be better to just replace the pump at some point.

 

[TheBigWhit]

Al was blamed for increased risk for AD. A lot of people threw out their Al cooking pans in response. Epidemiological study showed no significant relationship to tau protein amyloid plaques or twisted tubules/tangles. The more significant risks are basically the same as for atherosclerosis plus having the wrong parents. Any effect from Al is overwhelmed by those risk factors.
I’m not a hydrologist just a lowly neurologist. As said through out my postings -

Correlation does not prove causation

And I sincerely appreciate your opinion. Thank you.

After the last 18 months watching the debacle unfold and the sad state of politics being injected into medicine I am reluctant to quickly accept any studies. Who knows who is telling the truth anymore?

 

[Simi 60]

Yes sir, a passivation filter between RO and tank will help improve the situation provided all the chemical is not consumed before the pump. A steel watertank would likely plate out and consume 100% and leave the pump unprotected. You can only get so much calcite/corrosex into solution before the conductivity will exceed potable limits. Thats where zinc orthophosphate comes in. But its a PITA to apply requiring a tank, mixer and injection pump. Might be better to just replace the pump at some point.

Should have said, pump is it for the metal
Tanks and pipes are all plastic.
Thanks.

 

[Hippocampus]

Big don’t read opinions. Read the source studies. Either the study is statistically significant or not. Either the study has confounders or not. Just like in engineering the bridge falls down or not in medicine there are facts and then opinions. Yes, you need some basic knowledge about study design and statistics to judge the strength of a study and familiarity with the language commonly used in the conclusion section but it’s not opaque. We do prescribe medicines, give advice or do surgery on the basis of known fact. Our understanding evolves. At first Al was suspect now not a major concern. First aspirin was thought to prevent stroke and myocardial infarction. Now we know that’s true but unless you have a certain level of risk factors that known true benefit is overwhelmed by the risk of bleeding. You add facts upon facts. People seem to confuse the evolution of knowledge with shifting or competing opinions. Intelligent people like you will hopefully let their thinking evolve as knowledge evolves.

 

[Alaskan Sea-Duction]

A lot of talk of the science of water. I would agree in 3rd world counties water is a big thing. Here in the U.S. not as big of an issue. Even less of an issue with recreation boating with water makers. Unless you want to buy a bunch of unnecessary equipment to stay up with the Jones.

So back to water maker options.

 

[dhays]

Sorry for these long posts folks but water is a complex subject...

pfft... its just a oxygen atom with a couple hydrogen hitchhikers. How complicated can that be?

 

[ksanders]

A lot of talk of the science of water. I would agree in 3rd world counties water is a big thing. Here in the U.S. not as big of an issue. Even less of an issue with recreation boating with water makers. Unless you want to buy a bunch of unnecessary equipment to stay up with the Jones.

So back to water maker options.

After reading this thread one might throw out their watermaker in fear of corroding their system, or dying of malnutrition.

I'm just going to continue my happy life using my watermaker daily, in blissful ignorance.

 

[twistedtree]

Here is a chart that depicts metals hierarchy. The top is most sacrificial to bottom most noble. Combining different metals in the same solution can create other problems. Plastics are a great solution provided its material that wont itself leach. HDPE, PET, Delrin, Celcon and to a lesser extent PVC are good alternatives.

But I think that's a galvanic chart, not a corrosion chart. Or did I misunderstand earlier about what sort of reaction is going on?

 

[lwarden]

Hey Whit, welcome to the site!
(lwarden AKA Inboardman)

You know now you've done it, now that you've let the cat out of the bag on your background every watermaker/water problem you are going to be summoned up like the Genie from the lamp.

Or like Peggie Hall (Headmistriss) get's called up when someone has a poo tank problem.

Anyway, good to see you over here my friend.

 

[TheBigWhit]

But I think that's a galvanic chart, not a corrosion chart. Or did I misunderstand earlier about what sort of reaction is going on?

I'm not sure I follow the question. Did I get something wrong (which I'm very capable of doing).

 

[TheBigWhit]

Hey Whit, welcome to the site!
(lwarden AKA Inboardman)

You know now you've done it, now that you've let the cat out of the bag on your background every watermaker/water problem you are going to be summoned up like the Genie from the lamp.

Or like Peggie Hall (Headmistriss) get's called up when someone has a poo tank problem.

Anyway, good to see you over here my friend.

Thanks for the warm welcome. Good to see you. Did you get the new boat home safe and sound?