Water Maker options

[ksanders]

That’s been my practice as well Kevin. Except would have pickle solution recycle through the machine for ~10 minutes. Both draw and return placed in that bucket.
Machine is new to me. No manual on board. Don’t sure which valve and where. Machine is a SeaRecovery. What’s yours?

Mine was designed by Cruise RO from off the shelf parts.

I went with 40 GPH in order to get redundant membranes

 

[Porgy]

Your body can't absorb minerals from water so having minerals in your drinking water does nothing for your health. This may sound controversial but its a fact. Water in the body is used to maintain electrolytic balance of your electrical system and flush your kidneys of waste. The purer the water the higher the osmotic pressure thru your kidneys flushing more contaminants.

I’m confused. I thought I just read here from a doctor who seemed to know about the human body, that we do get minerals from water. I started reading an NIH report on minerals in drinking water. While I’ve only gotten through a few minerals so far, it’s 233 pages long, it was pretty clear that minerals in drinking water do contribute to nutritional requirements. I had biology and zoology in college but that’s as far as my knowledge goes.

 

[Pier Pressure]

Sorry to this, ask I did a search. Trying to get educated on what is available out there on water makers. I have been reluctant as we have 800 gallon tankage, but the wife wants us to have a Watermakers (what she thinks is more independence.) We have 10KW gen set, massive battery bank and proper inverter set up.
Do you love yours? What is it? I am blessed with engine room with room. So room and power should be no problem. I'd lean to a larger capacity to run less hours if that works in the watermaker world. So let me know what you love or hate or? About your water makers?
[/ATTACH]

We installed a Cruise RO this summer, 40gph 220v hp pump 12v lp pump. Simple to install, easy to use. Highly recommend it. Only do over would be a 120v lp pump.

 

[Hippocampus]

Porgy what I posted and what you read is correct. Although food does supply minerals and especially simple salt (NaCl) most trace minerals comes from your water. The driver of urine formation is the sodium potassium pump. The comments about the osmotic gradient are completely incorrect. Kidneys filter blood. The osmolality of blood is very tightly controlled. The osmolality of blood will not vary as long as you’re anywhere close to decent hydration. One of the main jobs of your kidneys is to maintain the strict osmolality of your blood. They will vary the concentration of your urine to maintain that regardless of the osmolality of the fluids and food you ingest.
The UN published an extensive review of the potential health risks of drinking exclusively RO water in response to many parts of the world becoming increasingly dependent upon desalination plants. This is becoming a major issue as rainfall patterns are shifting from MMCC. Some think access to water is and will be a driver for mass migrations and war. Here in the US the migration from Central America to North America is in large part due to the absence of water and arable land causing migration to their cities and then due to crime to us.
It’s probably that UN document or a extract that you were reading. I would believe that summary document above what I or others say.
A good read to understand glomerular filtration is in “Principles of Medicine “ or a simple google search. Think prior poster was a bit confused about the concept of free water ingestion.

 

[TBill36]

Haven't read the entire thread so apologize if this was discussed. Normal tap water has chlorine in it to keep critters from growing in it or the delivery system. So when I return from cruising, I fill my tanks with tap water as the RO is too pure and more susceptible to getting contaminated. Annual flushing is also a good preventative, but I don't like leaving RO water in my tanks for extended periods of time without using it.

 

[Hippocampus]

At the galley sink and at the pressure pump we had filtering systems. Even using shore water if you’re traveling think it’s a good idea to have a whole boat filtering system ( showers and even washing the deck is better) as well as a really good one at your galley faucet (or separate spigot). Carbon filters take out the chlorine and there’s non chlorine based germicides you can use. Many in the RV crowd prefer to avoid chlorine in their tanks.

 

[Porgy]

Thanks HC. I’m spending the rest of the day walking around saying glomerular osmolality.

 

[TheBigWhit]

I’m confused. I thought I just read here from a doctor who seemed to know about the human body, that we do get minerals from water. I started reading an NIH report on minerals in drinking water. While I’ve only gotten through a few minerals so far, it’s 233 pages long, it was pretty clear that minerals in drinking water do contribute to nutritional requirements. I had biology and zoology in college but that’s as far as my knowledge goes.

Its quite obvious that doctors have many different opinions and studies can be found to support just about any position. I'm not here to argue with another doctor or prove a point. I simply wanted to provide some data to help clear up some misconceptions on the topic of water and marine RO units. Have a great day.

 

[catalinajack]

Haven't read the entire thread so apologize if this was discussed. Normal tap water has chlorine in it to keep critters from growing in it or the delivery system. So when I return from cruising, I fill my tanks with tap water as the RO is too pure and more susceptible to getting contaminated. Annual flushing is also a good preventative, but I don't like leaving RO water in my tanks for extended periods of time without using it.

We have lived aboard full time for six years. Except for maybe a few times while doing the loop our tanks have not seen chlorinated water nor have we put any bleach in our tanks. Nope, haven't been sickened yet. Think about this. Millions of homes use well water. Well systems pretty much all have pressure tanks, smaller than any boat's tanks to be sure, but tanks all the same. Yet, does anyone even give that a thought? And, I'll bet a dollar that some boaters who angst endlessly about critters in their tanks also have well water in their homes but never think about sanitizing their pressure tanks or their water pipes for that matter. Much ado about nothing.

 

[Porgy]

As a liveaboard I don’t worry about it either in large part because our water is constantly being used and refilled. In 9 years I haven’t had to clean or chlorine shock, etc. At one point I was carbon filtering city water as I filled the tanks (my wife is acutely sensitive to chlorine taste.) All good. However, in some low spots in drains and shower strainer, etc. with some minor standing water, I noticed swamp monster algae here and there. Something that wasn’t there with straight city water.

My speculation is if you use your water you have less likelihood of an issue. If you let it stand for some length of time (weeks, months?) it might need some attention. Could also be true for chlorinated water that stands as the chlorine will eventually dissipate. You can add chlorine dioxide which is more stable than Clorox.

 

[Hippocampus]

The two major things that improved life expectancy were clean water and human waste management. Not antibiotics or anything doctors did. Infectious diarrhea remains a leading cause of death throughout the world. First world folks are blessed they can assume the water they drink from municipal supply or draw from the ground won’t kill them. That isn’t true elsewhere in the world.
I not arguing here. I’m stating simple repetitively confirmed scientific facts. “Science doesn’t care what you believe”.
I’ve lived on well water. Uncontaminated by fecal waste, industrial byproducts or radioactivity. If the substrate water is clean and healthy only then do you need to be concerned about how it’s stored. If the substrate water is unhealthy mode of storage is irrelevant. It must be made suitable for human consumption first.
Returning to RO water my prior concerns were aimed at folks who consume exclusively RO water for long periods of time. These is a concern for long term cruisers but not for most here.
Like CJ we never put chlorine in our tanks. Had 200g and a watermaker. Then whole boat filtration. Turn over time of our two water tanks was sufficiently rapid that even if there were biological contamination colony counts would be low. Given we didn’t take on outside sources risk of contamination was low. (Basically vents which were inside the boat.). Add in filtration and total risk was very low. One year we did store on the hard inside the hurricane zone and went home. For that time drained the entire water system. Upon return did fill tanks with heavily chlorinated water but then drained that and refilled flushed refilled flushed several times. We carry a filtering system you can attach to the shore water source so you decrease risk of contamination.
Agree with CJ. If your system starts out as sterile and you keep it sterile biocides aren’t necessary.

 

[ksanders]

Hmmm Dangerous to drink RO water???

First I am not a doctor, and even a regular MD probably has zero training or experience regarding RO water. That just makes sense unless one specializes in water quality science.

What I am is a relatively intelligent person and as such it is really easy for me to determine that drinking pure water from my watermaker is as least as good and probably better for me than drinking municipal water in many places that has has chemical additives mixed with it or is of otherwise dubious quality.

With regards to minerals I never really considered the lack of minerals in the RO water that I have been drinking for several years. Just thinking logically I think that a balanced diet probably supplies most if not all minerals my body needs.

I could be wrong, but I'll take the pure water that I desalinate any day over filtered water bottled by some giant corporation in a huge plant somewhere.
Water that in reality probably comes from a municipal water system in a place far away and out of my control.

 

[ronobrien]

The two major things that improved life expectancy were clean water and human waste management. Not antibiotics or anything doctors did. Infectious diarrhea remains a leading cause of death throughout the world. First world folks are blessed they can assume the water they drink from municipal supply or draw from the ground won’t kill them. That isn’t true elsewhere in the world.
I not arguing here. I’m stating simple repetitively confirmed scientific facts. “Science doesn’t care what you believe”.
I’ve lived on well water. Uncontaminated by fecal waste, industrial byproducts or radioactivity. If the substrate water is clean and healthy only then do you need to be concerned about how it’s stored. If the substrate water is unhealthy mode of storage is irrelevant. It must be made suitable for human consumption first.
Returning to RO water my prior concerns were aimed at folks who consume exclusively RO water for long periods of time. These is a concern for long term cruisers but not for most here.
Like CJ we never put chlorine in our tanks. Had 200g and a watermaker. Then whole boat filtration. Turn over time of our two water tanks was sufficiently rapid that even if there were biological contamination colony counts would be low. Given we didn’t take on outside sources risk of contamination was low. (Basically vents which were inside the boat.). Add in filtration and total risk was very low. One year we did store on the hard inside the hurricane zone and went home. For that time drained the entire water system. Upon return did fill tanks with heavily chlorinated water but then drained that and refilled flushed refilled flushed several times. We carry a filtering system you can attach to the shore water source so you decrease risk of contamination.
Agree with CJ. If your system starts out as sterile and you keep it sterile biocides aren’t necessary.

The earth is a natural filter. Think about this; water is not "made" anywhere. It is simply here and being reprocessed over & over for eons. We are drinking 65 million year old dinosaur pee.

 

[Hippocampus]

Kevin google it. There’s a host of science showing being dependent upon demineralized water (either from wells, ground water or RO) has proven adverse health effects. BTW one of my son in laws is a water engineer. In his service region municipal RO plants remineralize their water. You remineralized your RO water by drawing Ca, Mg and trace elements from your bones and other fixed structures. Like you I am less worried drinking RO water than shore water in many of the places we’ve been. But we pay attention to demineralization. Buy small packets. Throw one into the gallon jug in the frig we use for drinking water. A total non issue. Don’t know if you’re off grid in Alaska for long periods of time. As said repetitively this is really only a concern if demineralized water is your only source of free water for long periods of time.
The health concerns about total dependence upon demineralized water isn’t controversial. Don’t make it so. Also realize it’s a concern very few posting here need to worry about.
Basic citation https://www.who.int/water_sanitation_health/dwq/nutrientschap12.pdf

 

[Hippocampus]

R what you say is true except repetitively even in NA aquifers are contaminated so well water is unsafe for human consumption. Worldwide the situation is worse.
https://www.who.int/news-room/fact-sheets/detail/drinking-water

 

[ksanders]

Kevin google it. There’s a host of science showing being dependent upon demineralized water (either from wells, ground water or RO) has proven adverse health effects. BTW one of my son in laws is a water engineer. In his service region municipal RO plants remineralize their water. You remineralized your RO water by drawing Ca, Mg and trace elements from your bones and other fixed structures. Like you I am less worried drinking RO water than shore water in many of the places we’ve been. But we pay attention to demineralization. Buy small packets. Throw one into the gallon jug in the frig we use for drinking water. A total non issue. Don’t know if you’re off grid in Alaska for long periods of time. As said repetitively this is really only a concern if demineralized water is your only source of free water for long periods of time.
The health concerns about total dependence upon demineralized water isn’t controversial. Don’t make it so. Also realize it’s a concern very few posting here need to worry about.
Basic citation https://www.who.int/water_sanitation_health/dwq/nutrientschap12.pdf

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.

 

[OldDan1943]

and dont forget the city in MI and their lead water pipes.

Maybe it is time for us to by a small distilling plant for our homes?

 

[Alaskan Sea-Duction]

Hmmm Dangerous to drink RO water???

First I am not a doctor, and even a regular MD probably has zero training or experience regarding RO water. That just makes sense unless one specializes in water quality science.

What I am is a relatively intelligent person and as such it is really easy for me to determine that drinking pure water from my watermaker is as least as good and probably better for me than drinking municipal water in many places that has has chemical additives mixed with it or is of otherwise dubious quality.

With regards to minerals I never really considered the lack of minerals in the RO water that I have been drinking for several years. Just thinking logically I think that a balanced diet probably supplies most if not all minerals my body needs.

I could be wrong, but I'll take the pure water that I desalinate any day over filtered water bottled by some giant corporation in a huge plant somewhere.
Water that in reality probably comes from a municipal water system in a place far away and out of my control.

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.

I do agree with Kevin. Hippo, good article.

After using an RO system for a number of years, I have no issues. In fact when I test my RO water, most of the time it has less particulates than one of the "Zero" water pitchers or tap water. I have drank cool clear mountain water which has more junk in it, so I prefer RO water, no chemicals added.

No big science thing here. RO is great water. If fact the best place I have made water is Frederick Sound. Deep and cold clean water!!!

 

[Hippocampus]

Sailing acquaintance fell maybe 2’ going up his companionway steps. Broke a bunch of ribs. His doc thought it odd a healthy middle aged man would break ribs with such a trivial fall. Only Med a weak diuretic (hctz) at low dose for HTN. Did a bone density. He had severe osteoporosis and was lucky he didn’t have hip or vertebrae fractures yet. Has been living on his boat. Only RO water as he doesn’t want to pay the 35cents/g for shore water in the Caribbean. After a w/u doc believes reason for his osteoporosis is demineralization related to his only drinking RO and perhaps a minor contribution from his hctz. Guy said he also notes his energy level and mental acuity is better now that he has supplemented. Just saying…….

 

[socalrider]

and dont forget the city in MI and their lead water pipes.

Maybe it is time for us to by a small distilling plant for our homes?

I have one of these under our kitchen sink. Keep meaning to run it to the refrigerator for ice and cold water but haven't done it yet.

It has a re-mineralization cartridge that adds back the minerals RO takes out. Per HC's very helpful (and a bit scary!) posts, perhaps this is something that could be plumbed into a boat's water system for those who live aboard and rely 100% on RO water? Looks like Amazon has them for $25.

 

[TheBigWhit]

The use of words here being undefined make discussing the topic difficult. "De-mineralized" is one. SWRO is not by definition a "de-mineralizer". Typically demineralization is performed in high purity water systems using ion selective resins. Some use ion exchange resins like that used in water softeners.

RO membranes reject ions in the feed water to varying degree. None are rejected 100%. Typical membranes produce permeate from 36,000 ppm TDS typical 77F sea water of around 225 ppm TDS (around 99.8% rejection). As membranes age, compact and foul/scale through use and lack of sufficient maintenance, permeate quality will increase as the polymers age. We typically replaced membranes in the 750 ppm to 1000 ppm TDS range in potable systems. Not every membrane in a multi membrane system fail at the same rate nor perform equally for various reasons. There are many different membranes available; high rejection, high flow, selective rejection, etc. Each batch of membrane sheet also has its own unique characteristics although QC and manufacturing techniques over the past 30 years have reduced this issue.

The "anti-RO" hysteria that has led to the concept that RO water is unhealthy was started by an eco-terrorist group on the island of Malta years ago that tried to stop a large muni project. Ultimately this group was anti-development and wanted to stop any immigration or tourism and lack of potable water is a key manipulator. These tactics have been adopted around the world and confront every major desal project. Ultimately the projects usually proceed as the anti-RO groups are proven wrong time and again.

The reason municipal and other large land based RO facilities add "remineralizing" chemicals to the water is not for body beautiful or any public health issue. It is added to control and increase the LSI and reduce corrosivity of the water. The focus is on maintenance and longevity of underground metal piping systems and metal components in public water systems. This is also one of the primary uses of fluoride in public systems even though we are told by "professionals" in government its for your teeth. Post treatment is primarily about corrosivity and objectionable taste/odor in public supply.

As for long term consumption of RO water, I installed an RO on my home in 1999 using shallow well water as feed. Conductivity varies over the year due to seasonal rainfall between 400-3,000 ppm TDS. Light brackish but high iron and other objectionable constituents. My permeate quality varies between 8-30 ppm TDS, basically distilled quality which is typically <10 ppm. My family has been consuming this water solely for 22 years. Yearly lab tests indicate my water is excellent and far better than most municipal supplies and certainly equal to or better than bottled waters.

Any boat that primarily uses RO water in the tanks would be wise to install a calcite type "remineralizer" filter as RO post treatment. Not for any human health issue whatsoever but to help protect metal tanks, piping, faucets or other metalic system components from the corrosive RO permeate. It may take years but RO permeate will corrode metalic pipes and damage washing machines and dishwashers as well.

Hope this helps answer some questions.

 

[rgano]

I was captain of an oceangoing tug in another life, and we had a waste-heat water maker. Anytime one of the four big Cat D399s was running we had enough heat to boil the seawater for subsequent condensation to freshwater. Our 69-man crew never suffered water hours as I occasionally experienced on destroyers. Here is a website which offers a large range of capacities https://www.maximwater.com/evaporators.html.

 

[OldDan1943]

r subsequent condensation to freshwater. Our 69-man crew never suffered water hours as I occasionally experienced on destroyers. Here is a website which offers a large range of capacities https://www.maximwater.com/evaporators.html.

When I was on the DD881 we were never on water hous but we did have a very limited HW for the MMs. The ship was so very old, many parts were just not available anymore. One non-existing part was the pump to recirculate water for the HW system servicing the aft shower. So unless you were first, you took a quick cold cold shower.

 

[Hippocampus]

Thanks Big. Will note I’m a big fan of watermakers and have had them on the last several boats as stated here several times. The spectra cape Horn extreme ran at 75-100ppm but as you say higher is quite acceptable. That machine had 2/week use and was back flushed after each use. Will note in prior story gentleman was on a salt wasting diuretic (dock side conversation so have no further details). Still, find RO water tastes flat so see no problems adding minerals to the jug we keep in the frig. Repetitively have said think it highly unlikely but for a few there’s a risk for folks here. You’re spot on about adding minerals to protect tanks and fittings. Need to chat up my son in law about trace elements and Mg. The Malta story is fascinating background. Thanks for adding that.

 

[TheBigWhit]

Nothing at all wrong with adding taste modifiers to drinking water. A client paid a fortune to add a bottling line with a brand that tasted like Fiji Water. That was challenging adding all the hardness to match Fiji chemistry while not exceeding potable limits on saturation. Took about 6 months of experiments before we perfected it. Interestingly we found that higher carbonates made you thirsty quicker. The more you drink the more you want.

 

[Bigsalmonfish]

We put a 20 gph AC watermaker in 20 years ago to feed the consumption of a family with 3 little kids, laundry etc. Best money ever spent. 7 years ago we added a pressure vessel and membrane to increase output to 40 gph. This was to feed the teenagers ability to take showers, laundry etc. I felt that 13 years on the original membrane was enough and replaced it when adding the other. During that time and per the instructions of the manufacturer we NEVER have pickled. It is either used or flushed weekly with water that has NO Chlorine. I fill the tanks occasionally with city water and the chlorine present takes care of anything in the tanks. I then let it "boil" off for a week before starting the back flush of the system. Never a problem with water quality. My only gripe has been the plugging of prefilters in the West Coast in areas. I do the multiple filter gig. This year I had a plankton filter installed and it's too early so far for a final judgement on its effect. I am still seeking a small sand filter. Now our kids are gone to college and we have a huge surplus of water. Boat wash and laundry are done frequently and I beg people to take water. My synopsis is to keep the system simple. NO electronics, flush every two weeks, use it often

 

[rgano]

When I was on the DD881 we were never on water hous but we did have a very limited HW for the MMs. The ship was so very old, many parts were just not available anymore. One non-existing part was the pump to recirculate water for the HW system servicing the aft shower. So unless you were first, you took a quick cold cold shower.

An old DD converted to DDG I was on developed a crack between our big potable water tank and a fuel tank (POOR design). As we were on station in the Tonkin Gulf and could not leave, the water was "tested" and we were told it was ok to drink. I would only drink that nasty stuff after a bunch of "koolaid" powder had been dropped in and even then you had to hold your nose.

 

[TheBigWhit]

We put a 20 gph AC watermaker in 20 years ago to feed the consumption of a family with 3 little kids, laundry etc. Best money ever spent. 7 years ago we added a pressure vessel and membrane to increase output to 40 gph. This was to feed the teenagers ability to take showers, laundry etc. I felt that 13 years on the original membrane was enough and replaced it when adding the other. During that time and per the instructions of the manufacturer we NEVER have pickled. It is either used or flushed weekly with water that has NO Chlorine. I fill the tanks occasionally with city water and the chlorine present takes care of anything in the tanks. I then let it "boil" off for a week before starting the back flush of the system. Never a problem with water quality. My only gripe has been the plugging of prefilters in the West Coast in areas. I do the multiple filter gig. This year I had a plankton filter installed and it's too early so far for a final judgement on its effect. I am still seeking a small sand filter. Now our kids are gone to college and we have a huge surplus of water. Boat wash and laundry are done frequently and I beg people to take water. My synopsis is to keep the system simple. NO electronics, flush every two weeks, use it often

A really nice and robust prefilter for marine use is a 5” x 20” Big Blue housing adapted to use 3” x 18” standard size polypropylene bag filter in 5 micron. My cost for these are under $200 and bags are cheap. Huge sand and particulate capacity. The bag filter followed by a 5M cartridge is all most boats need so you can get rid of the high priced “oil” filters and swimming pool filters. Nice and compact too.

 

[twistedtree]

I’d like to understand the corrosion issue with RO water. What’s the chemistry? I was told that RO water is “hungry for minerals”, but I’m looking for an explanation above the third grade level. You guys seem to know...

 

[TheBigWhit]

I’d like to understand the corrosion issue with RO water. What’s the chemistry? I was told that RO water is “hungry for minerals”, but I’m looking for an explanation above the third grade level. You guys seem to know...

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...