Water Maker

I have 1000 gallon storage and want to add a water maker to get the tanks topped up. Also I want to use more fresh water for washing down the boat more often.

What size would you recommend and which brand. Anything I need to keep an eye out for.

"Anything I need to keep an eye out for."

A long and tedious (and expensive?) procedure requirement to NOT use the unit.

Get the operation and maint manual BEFORE purchasing anything with complex instalation , maint or out of use requirements.

Oceaneer55 said:

...What size would you recommend and which brand. Anything I need to keep an eye out for.

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We are on our 2nd water maker. Think GPH not GPD. Our current water maker is ~26 GPH. You may want ~50 GPH. The water-maker is usually on when the generator is running.

Go AC not DC.

You can go simple like the Village Marine No-Frils or fully automated. We vote for simple and cheap (er).

No Frills Series Watermakers

LT Series Watermakers

Village Marine has good support. They are the main supplier to the CG and Military so they have several offices on either coast and Hawaii.

The big complaint I have and hear about the most is that Village Maine sells there own pressure vessels and membranes. If you need to replace the membrane it is about double what you pay for a Dow Fibetec membrane. What Village Marine does is have membranes made that are shorter than the industry standard so you have to buy one of theirs.

There are lots of quality water-maker companies out there. The boat shows are the best place to look and see.

Making your own water is not cheap, but it may be worth while if dockside water is not available, inconvenient or poluted. Basic RO (reverse-osmosis) desalinators are not complicated, but they must be used regularly or "pickled" to prevent membrane damage (I think that's what Fred is refering to).

I have a no-frills 10 gal/hour water-maker from Quality Water Works (pics below). This is a relatively inexpensive setup because the components (hi-presure pump, membrane, valves etc) are all available over the counter. George Walker, who founded the company, answers all email personally and is very helpful. I agree with Larry M about AC not DC although driving the hi-pressure pump off the engine (belt and clutch) might be worth considering, depending on your cruising style.

Mike: Nice clean install. That goes for the engine room also.

We went with a Katadyn 6 GPH model.

The unit works great and is a DC model. Very simple to use, a couple of valves and I added a flow meter to the ourput.

The only issue I have is the pump noise. Thump, thump, thump when it runs. Things can be really quiet on the boat, so with that unit running its a constant disturbance.

The best way I've found on the hook is to use like others have said when the generator is running. I seem to use about the same amout of water as it'll make during the generator run time (about 6 hours a day) so its not inconvient.

Go simple and cheap.
Best thing I ever did.
About 5 years ago I cut my water tanks in half down from 2 x 1000 lts to 2 x 500 lts.
Installed a locally made 120 lt/hr (30 gal) 2 membrane water maker with s/s HP pump. $8000.00 (Aus)
Only pickle it if leaving idle for more than 3 months other wise just flush it with good self made water (no chlorine etc)
I have installed a small in line ppm meter ($65.00) that measures the output from each membrane.
When it is below 400 ppm I switch the product water over to the tanks.

Google make your own water maker for a good overall description.
Other than 240 V (110 V) go for a main engine driven HP pump

The sea water that dies in your toilet and then stinks , is thev same water you are filtering.

It is flushed when a unit is in constant use , but to sit for a time requires a procedure.

Know in advance what the work required is.

I'd go with any of the stuff by Parker Racor. They now own Village Marine and HRO (seafaris). Durable, reliable, easy to use and maintain. https://citimarinestore.com/en/19-marine-watermakers-for-sale

The Little Wonders are on the lower end of pricing, LTs are a bit higher, Seafaris are somewhere in the middle / upper range. Can't go wrong with any of them.

And as others have mentioned, building one yourself out of the main components isn't all that terribly complicated, and can save you some $. Good guide on how to make one yourself, here: https://sublimesustenance.files.wordpress.com/2012/03/how-to-build-your-own-watermaker.pdf

Larry M said:

The big complaint I have and hear about the most is that Village Maine sells there own pressure vessels and membranes. If you need to replace the membrane it is about double what you pay for a Dow Fibetec membrane. What Village Marine does is have membranes made that are shorter than the industry standard so you have to buy one of theirs.

There are lots of quality water-maker companies out there. The boat shows are the best place to look and see.

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We have all Sea Recovery and are very pleased. The biggest criticism we hear also is proprietary membranes. First, if using good pre-filters and maintaining your system well, membranes last a very long time, especially quality ones like Village and Sea Recovery.

However, Acqua Primo , offers membranes for any of these now. This is a change in the last couple of years. They're actually made by osmosistech. Still not cheap but much cheaper than the original.

There are a lot of good watermakers. I like Sea Recovery on the larger units but others are equal on smaller units. However, in comparing to others, we have far fewer problems and the reason, in my opinion, is getting commercial grade pre-filters. If you use much in marinas then oil water separators are worth their weight in gold. And, if you're in certain areas (such as the west coast) then plankton filters are very valuable. I think the keys to performance are not just the watermakers but accessories in the form of additional filters.

I have a Village DC modular unit that has worked fine for the last 8 years it's been in the boat. I'm replacing the membrane this winter as a preventative maintenance item, but otherwise it has been bulletproof. Parker Hanafin now owns Village Marine and I'm not sure if that is a plus or minus for the Village products.

I am going to disagree with most of you. I didn't go cheap, I went fully automatic. My HRO self flushes after every use. It also self flushes every 7 days. I turned off my unit for 1 year. I full expected to find the membrane totally pluged. It was not, infact it had the same pressure readings as when I unplugged it a year earlier. Nothing pickles a water maker better than using water made by the water maker.


The most important thing to consider is the the avialability and cost of a replacement membrane. Make sure you pick a unit that uses standard size membranes.


My unit makes 25 gal per hour and I use 50 gal a day so that two hrs of run time each day. I find that acceptable but not every one else will.

tiltrider1 said:

The most important thing to consider is the the avialability and cost of a replacement membrane. Make sure you pick a unit that uses standard size membranes.

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Our membranes cost twice as much as others, but last three times as long. Don't see how that's a negative. Also, as I answered earlier, there are now companies offering replacements for any membranes.

To me the important thing is a system that does a good job and is relatively problem free.

BandB said:

Our membranes cost twice as much as others, but last three times as long. Don't see how that's a negative. Also, as I answered earlier, there are now companies offering replacements for any membranes.

To me the important thing is a system that does a good job and is relatively problem free.

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Why do they cost 3 times more, are they 3 times bigger?

tiltrider1 said:

Why do they cost 3 times more, are they 3 times bigger?

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They are large, but they're very high quality. It's demonstrated in how long they last. We've not yet ever replaced one but then our oldest one is 3 1/2 years old. 10 years is not at all unheard of. We've gone for complete Sea Recovery systems, automatic, all the other specialty filters as well. We use a lot of water and the vast majority of it is from the watermakers. There are those who will argue that other than size, there is nothing special about the filters. I am not a scientist and haven't torn any apart, but performance is tops. Even the other party now making a replacement filter charges more for it than their other filters and claims they do so because they match OEM quality.

Someone else posted above about proprietary filters from another Parker owned company (Sea Recovery is Parker Hannifin owned) and said they changed their membrane after 8 years but they were sure it could have gone ten. Regardless, the cost of a membrane spread over it's life is just not the factor I would make my buying decision on.

Look at your usage, at the water situation. If you have Plankton then you need a filter in line to handle it. If you're going to encounter oil, then you need something for it. Most of all, the membrane is preserved based on the quality of filter in the line before it and commercial grade filters will save a lot of trouble and cost. Don't think of it as one piece of equipment, but as a total system. If you only use on rare occasions and always offshore in clean water, your needs are far different than ours are.

For a year I saw Crusty (Pairadice) use the water maker below. 40gph! I installed one last spring and I am very very happy with it. Ran the heck out of it and never had an issue.


Cost is around $6k, Easy to install.


Cruise RO Water & Power: Watermakers for Boats & Yachts

Alaskan Sea-Duction said:

For a year I saw Crusty (Pairadice) use the water maker below. 40gph! I installed one last spring and I am very very happy with it. Ran the heck out of it and never had an issue.


Cost is around $6k, Easy to install.


Cruise RO Water & Power: Watermakers for Boats & Yachts

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They have a large number of happy users. Curious, do either of you have the auto flush and/or the remote valving and cleaning panel?

BandB said:

They have a large number of happy users. Curious, do either of you have the auto flush and/or the remote valving and cleaning panel?

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Nope, we both have basic systems. Less things to go wrong and easy repairs.

Crusty Chief said:

Nope, we both have basic systems. Less things to go wrong and easy repairs.

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And cheaper.

Tidahapah said:

Go simple and cheap.
Best thing I ever did.
About 5 years ago I cut my water tanks in half down from 2 x 1000 lts to 2 x 500 lts.
Installed a locally made 120 lt/hr (30 gal) 2 membrane water maker with s/s HP pump. $8000

Click to expand...

Wouldn't go simple and go cheap be leaving your larger water tanks in and use a tap?
It'd be real easy if tying up to a berth every couple of weeks.

We live aboard full time on the hook and don't have a water maker.

You can change out both the Village Marine RO membrane housing and the membrane when the original membrane craps out. For the cost of single VM membrane you can replace both the housing and the membrane with standard (40 inch) length units. Then next time the membrane is far less costly than the VM unit. The VM membrane is almost certainly not made by VM. Their sales/production volume is far too low to justify the production equipment cost etc. The best membranes are made by Dow/Filmtec that likely manufctues the VM membranes as well. I had thought that VM had actually discontinued the practice of gouging customers by using a proprietary 38inch membrane/housing when the rest of the world uses a 40 inch standard.

Spectra not so bad

The previous owner installed a spectra Newport 400 unit on our boat. It’s functionality is totally automated. I turn on the unit and tell them how many hours to produce water and it does everything else, to include monitoring water salinity and automatically back flushing the system when finished. I love the fact that through the automated head I can monitor all functions of the system.

We are currently in the Bahamas and making water on a regular basis on a 12 V system making 15 to 16 gallons per hour. Given the fact that we only use 25 to 30 gallons a day, without trying to conserve, this water maker is more than sufficient.

Since Parker bought VM the cost of the membranes have come down significantly. A 2.5"x40" Dow/FilmTec membrane is ~$205 vs the 2.5" x 39" Parker (Village Marine) which is ~$377. The first 39" membrane I bought was over $600. At $377, they're still expensive but if you get 5 plus years it's not a game changer imho. And Parker does have one of the better AC high pressure pumps.

I have a need for both hand-pumped and DC driven, separate contexts.

Is there a lower-cost membrane that can be used in good quality units for both use cases?

If you don't need automatic or don't want to spend lots of money...
I have about a 50 gph component system with the high pressure pump belt driven off a generator. I made mine a little at a time with many changes because I didn't know much about reverse osmosis. All my water maker experience was with steam evaporators.
I got a lot of bad advise, bought useless things, but eventually got there. Since I make water in salt, brackish and fresh, a really good membrane salesman had me buy a set of all 3. 6 total. I didn't know you just turned down the pressure for fresh.
I would have been thousands of $ ahead to buy a component system like Cruise RO. I still may. I don't really like running the pump on the generator. Now I have an inverter system that would handle an 240v pump and my water needs and electrical needs rarely are the same. I also have long water runs because there was no place for the membranes and filters near the generator.

Simi 60 said:

Wouldn't go simple and go cheap be leaving your larger water tanks in and use a tap?
It'd be real easy if tying up to a berth every couple of weeks.

We live aboard full time on the hook and don't have a water maker.

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That's my thinking as well.
It doesn't get much simpler and cheap easier than that.

I'm not sure on the size of my tanks but they'll last about 3 weeks on the hook with 2 people aboard. That's about as long as I plan on being out.

AusCan said:

That's my thinking as well.
It doesn't get much simpler and cheap easier than that.

I'm not sure on the size of my tanks but they'll last about 3 weeks on the hook with 2 people aboard. That's about as long as I plan on being out.

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I hold 210 gallons. Without a watermaker, you are forced to return to the dock sooner or later. With a watermaker we cane do laundry, take Hollywood showers. Extends our time away from port. I think the water is better too. We put 3700 sm on ASD this past summer.

Its really hard to fill up a boat's water tanks when the dock water lines are frozen or shut off for the winter.

I'll give another endorsement for Cruise RO. I just installed the 30gph model in my boat before heading to Mexico. The owner, Rich, answers the phone and spends as much time as needed answering questions. He helped me make a few changes in my set up that helped the system perform better. Although I originally ordered the auxillary fresh water flush system, I didn't end up using it. Rich refunded me for the unit. I have used the WM for a total of about 300 gallons of fresh water with no problems so far. I love this thing!

I have no commercial interest in this company, I am just a happy customer.

Cheers, Bill

So same guy who makes Technautics Cool Blue fridge systems.

Wow, I'm thinking this might be the guy to help me build this little dream system

A. DC gennie based off a HO alternator, say 200+A @ 12V

B. high capacity watermaker, salt, brackish or fresh

C. compressor for eutectic holding plate fridge freezer system

D. A/C maybe heatpump split/combi

E. air compressor


all driven off a quiet little dual-fuel (gasoline or LGP powered) engine

Packaged up as portable as possible, move from boat to expedition vehicle to cave or off-grid cabin.

Yes I realize B-E could be run off a battery bank, but with mobile solar, all the loads are pretty large, and often will be appropriate to perform 2-3 functions at the same time.

And wouldn't it be more space / weight efficient than carrying four extra DC motors around?

I know, I know, said I was dreaming