Water Maker (Desalinator)

After a recent 5 days on the hook, we went through a lot of water (even the dog got showers after frolicking in the surf...but that's an entirely different thread...).

Debating our needs for the future, one option would be a desalinator. Once on the hook, I would rather not pull anchor just to find a marina for fresh water. In some of our planned destinations, the shore water supply is either limited in quantity or quality. We could reduce our consumption but that would strain my domestic situation much more than my water supply !!

Our 1985 twin screw 38 foot Tiawanese trawler has enough room for the desalinators I have been researching, but just barely. We have a Northern Lights GenSet. When on the hook we typically run the generator 1-2 hours a day to top off our batteries and heat the water. This works well, and, of course, never requires us to pull anchor to look for a marina. It seems like it would also be a good time to run a desalinator and top off our FW tanks.

Currently we carry 170 gallons of FW in 3 tanks (with separate deck mounted fill spouts). One tank is under the aft master bed, with two smaller tanks on each side of the bed in the rear portion of the master cabinets. The tanks are metal (steel?) and I have limited physical access to the smaller tanks via the lazarettes. We do not have tank level sensors (yet).

My question of the Forum members is which desalinator system has worked well for them. There have been a number of threads on this subject in the past which I have read, but most are several years old, and technology changes.

We are not live-aboard or long distance cruisers. Our usual destinations are in the PNW islands. Thus, I would describe our usage as 1)seasonal 2)infrequent and 3) high volume when we actually turn it on. It would not surprise me if we end up making 30-40 gallons of FW per day during our summer cruises.

So, for those of you who are making their own fresh water, what advice would you give the newbie who is considering this installation?

Cruise RO Water www.cruiseROwater.com
Makes a good component system. They use standard filters and membranes. Their smallest is 20gph, so in 77°F water you'd get 40 gallons for two hours on your generator. The membranes are rated at 77° so in colder PNW water you'll make about 75% less than rated unless you use a heater to warm the water. I do.

There are others with everything in one box, but are 2-3x more expensive. Some use proprietary filters and membranes that are much more expensive.
The nice thing about component systems you can place the membranes, filters and pumps where it's most convenient.

Keep in mind that once you start using your watermaker, you need to use it at least every 7-10 days, or else run some chemicals thru it to preserve the membranes. It takes time to do this. Then before you use it again you will need to flush out the chemicals. The key word in your post is infrequent user.

Also, there will be places you do not want to use the watermaker because there is just to many boats in the area or the bay does not flush out well with the tide changes and there is a lot of algae in the water. I frequently make water while underway, out in open water, so to get as clean of water as possible to start with.

Russell Clifton said:

Keep in mind that once you start using your watermaker, you need to use it at least every 7-10 days, or else run some chemicals thru it to preserve the membranes. It takes time to do this. Then before you use it again you will need to flush out the chemicals. The key word in your post is infrequent user.

Also, there will be places you do not want to use the watermaker because there is just to many boats in the area or the bay does not flush out well with the tide changes and there is a lot of algae in the water. I frequently make water while underway, out in open water, so to get as clean of water as possible to start with.

Click to expand...

We are in the same boat as the OP (so to speak), and deep in research mode for a watermaker. One feature we want is having the system “self clean” by running product water thru the membranes keep them critter free.

Haven’t pulled the trigger yet, but soon...

We are also in the market for a watermaker. I have watched all the videos for the RO Water http://www.cruiserowater.com/ and found them to be extremely informative. Well done for the layman to understand how the system works and how to maintain it and generally what to expect. That is the system on the top of my list.

Bud

Bud said:

We are also in the market for a watermaker. I have watched all the videos for the RO Water http://www.cruiserowater.com/ and found them to be extremely informative. Well done for the layman to understand how the system works and how to maintain it and generally what to expect. That is the system on the top of my list.

Bud

Click to expand...

This is the link Sailboat Water Maker | Simple Watermaker | Cruise RO Water & Power

Russell Clifton said:

Keep in mind that once you start using your watermaker, you need to use it at least every 7-10 days, or else run some chemicals thru it to preserve the membranes. It takes time to do this. Then before you use it again you will need to flush out the chemicals. The key word in your post is infrequent user.

Click to expand...

This is not correct.

You need a water maker with an automatic flush cycle designed into it. I have a water maker, it gets used for 10 hours in summer and 4 hours in the winter. It’s never been picketed and works fine. I can’t recommend it as the company is no longer in business.

My neighbor has a Spectra. My neighbor is a live aboard and makes all his own water. I’ve been very impressed with the Spectra, after 12 years of making water weekly he is now replacing the membranes as preventative maintenance. He is a doctor who sometimes goes off on 4 month missions, all needs to do is make sure the tank has enough water in it for the auto flush.

I am really impressed with the Spectra water makers, you push one button to turn it on and you are done, no valves, no knobs, you can even set it up to run for a specific time and auto stop.

Spectra’s are not cheap.

Our watermaker is set up the same way. We just have to make sure that there is no chlorine in the water we fill the tanks with when the seawater is too dirty to desalinate. That means using a charcoal filter whenever filling from a dock.

A big benefit to RO water is that it is soft water with all pluses that go along with that.

tiltrider1 said:

This is not correct.

You need a water maker with an automatic flush cycle designed into it. I have a water maker, it gets used for 10 hours in summer and 4 hours in the winter. It’s never been picketed and works fine. I can’t recommend it as the company is no longer in business.

My neighbor has a Spectra. My neighbor is a live aboard and makes all his own water. I’ve been very impressed with the Spectra, after 12 years of making water weekly he is now replacing the membranes as preventative maintenance. He is a doctor who sometimes goes off on 4 month missions, all needs to do is make sure the tank has enough water in it for the auto flush.

I am really impressed with the Spectra water makers, you push one button to turn it on and you are done, no valves, no knobs, you can even set it up to run for a specific time and auto stop.

Spectra’s are not cheap.

Click to expand...

This is exactly what we’re looking for.

Well there you go. Get a Spectra waster maker.

A little watermaker background is needed folks. This will help folks understand what is happening.

When you run a watermaker you are bringing in seawater and extrascting the pure H2O from that seawater. The seawater is full of microscopic life. If you do not run the watermaker for a few days (longer in cold climates) that microscopic life dies. It then decays. Once the decaying process uses up the available oxygen in the seawater Anaerobic bacteria takes over which produces hydrogen sulfide gas. This gas is smaller than a molecule of H2O, and it is also harmeful to your membranes over time. Thats why why need to use, or flush, or pickle your watermaker.

Use, means just that use the watermaker every day or two and it will be just fine forever

If you cannot use it then another choice is to flush it with potable water every few days. You can do this using a solenoid valve and pressure water, or a solenoid valve and the watermakers low pressure pump. These would typically go on a timer.

Pickling the watermaker is the method I most often use. You use a food grade yeast killer which is a powder. You mix three tablespoons of the powder in a gallon of water and use your low pressure pump to suck it through the watermaker. This process takes literally 5 minutes.

Now lets debunk another myth, the clean water myth. The myth that you need pristine clean water to start with is pure fiction. Again, I stay aboard allot and my harbor turns off dock water october through april. I use the water right under my boat, and have done so for several years.

Yes watermaker membranes are suceptible to oil, and yes you see a bit of oil floating on the water sometimes in harbors. But think... my seacock is 4’ below the waterline and any oil is floating.

There you go, next post is about installation

Now lets talk about styles of watermakers.

A watermaker is simply a low pressure pump that feeds seawater to a high pressure pump that pushes the water through a membrane (think filter) that only allows pure H2o to pass through it. There are some filters before the low pressure pump, and some valves for flushing and pickling, but that is the basic idea.

There are two basic styles of watermakers, component, and enclosed. A enclosed watermaker is one where the manufacturer has put all the components in a box. The controls are typically on the front of the box. This is a pretty big box. I’m guessing here but at minimum 3’X2’X2’ to hold all the stuff.

These are easiest to install. Just hook up power, inlet water, brine water out, and produced water out. The challenge is running the thing. You need to actually see the control panel and turn a knob to adjust pressure to properly run a watermaker. If the box is in your bilge guess what, so are you to run it.

The other type is the component type. The things that make up the watermaker are all separate. You hook them together. This gives you a lot of installation flexibility as none of the components are all that large.

This is the type of watermaker that I have. I have the control panel mounted in my salon where I can get to it. The other components are in the lazarette.

The components are all easy to get to in case I have an issue. There are filters that need to be changed fairly regularly and these are right where I want them, not tucked somewhere that I need to do a hand stand to get to.

Before buying any watermaker you REALLY need to consider the installation. THINK about where the control panel is going to be. Picture yourself running the watermaker and plan your installation, and the type of watermaker you buy accordingly.

Next post we discuss propritary components.

We already discussed the main components that make up a watermaker, but lets now get into specifics.

Some watermaker manufacturers use components that they had built just for their watermaker. Those components are not used anywhere else on the planet. This is intentional folks. The intention is to make a profit, a huge profit on parts post sale. This makes you also dependent on that watermaker company still existing when you need that “special” component.

In short you are held hostage by your watermaker company.

Other watermaker companies use off the shelf readily available components. This gives you the freedom to buy things like filters, and new membranes, and pumps from whomever you choose.

I like this approach.

My watermaker uses standard 2.5X10” pre filters available at home depot. The pre-filter canister is also available there or at almost any home store in the country.

The low pressure pump is a jabsco unit. Available anywhere or replacable with any other brand of similar output pump.

The high pressure pump is is made by general pump. If it or the motor that drives it goes out, this is available from a bunch of sources, or I could choose another brand, no problem.

The membranes are dow corning 2.5”X40” standard off the shelf items, as are the membrane canisters. Google this sometime, there are literally hundreds of choices online to buy these membranes.

There is a lot to be said about having the flexibility of non proprietary components.

I bought my watermaker as a “kit” from Rich Boren over at Cruise RO water and power. I was impressed when I emailed Rich at 9:00 at night with a pre-sale question and he responded within just a few minutes.

After buying my watermaker I had several questions. Rich talked me through the installation process and troubleshooting a couple minor mistakes I made over the phone and via email. That kind of customer service cannot be beat! and that is why I am a very happy Cruise RO customer.

Thanks Kevin,
Couldn’t have said it any better myself! Ive had the Cruise RO system for almost 4 years now and customer service was the main reason for purchasing. As well as the ability to place the components where I had room.
One thing I would like to add. This was advise passed on by a Sailboater.
After making water and prior to backflushing with fresh water, remove the dirty filters, drain the dirty water from the canisters, install your “cleaned” filters, then do your back flush. Actually, the term backflush is not right. What your doing is using fresh water instead of raw water to run through the system.
By “cleaned” filters, all I do is spray most of the debris from the filters with my raw water sprayer at the bow. Then hang them up to dry. Then they become the “cleaned” filter next time. Sure the filters are fairly inexpensive, but I probably get 50 uses for each filter by just rinsing them.
You still need to flush with fresh water every 7 days if your not making water, but we almost allways were making water when cruising once a week, once we done cruising for the year, pickle the system and shut her down.
A fellow Selene owner was concerned that his fresh water was “disappearing” and the first question I asked was, do you have auto flush on for your water maker? Turned out he has auto flush set at every 5 days for almost a year!

Kevin
Great points and information. Regarding sea water quality, perhaps Seward's harbor is a lot cleaner than where OP anchors. In many parts of BC and WA the harbor water quality is not too good, unacceptable in our harbor for sure. A bit of experimentation with filters and membranes generally tells the tale as to water acceptance into the RO.

Ksanders, thanks for the refresher. It's been a couple of years since I studied up on WMers.

Kevin:Thanks for that great post. BUT... I then think about those boats in the marina that have liveaboards, or maybe just folks that spend a lot of time at the dock, and try to recall if I have ever seen a pump out boat service them or seen them untie and run out to the pump out station. There are probably a dozen liveaboards in our general area and the pump out boat tells me that he only services 3 of us. And then I remember places where I've seen drain pipes at low tide running out from the beach and wonder what that's all about. Last year I asked the folks at one marina in the Broughtons if all their floating homes had any kind of sewer system. She just kind of smiled and changed the conversation. Although I filter my water twice more after it leaves the water maker, I will still be real selective where I make water.

If your source water is not clear enough to see at least 3 feet, your pre-filter will be constantly clogging and throwing an error code. There was nowhere on the ICW that met this criteria so it’s been a while since we used it last.

I test my water and get excellent results, better than any city water when made from fresh. And better than city water except for tds when made from salt. I make water year round, the winters on the Columbia River. I have made water almost everywhere except big ports. I use washable mud filters and replaceable prefilters and a UV light sanitizer before the tanks.
Except for extra filters, my system is much like CruiseROs 40gph. I wish I would have bought theirs. It would have saved a lot of time and extra money. But now I know.

If money is no object and you want a push button system, buy a box system. But don't whine later about service and replacement parts cost. I don't wanta hear it.

There are a lot of YouTube videos on operating a watermaker. It's not rocket science.

options

I'm putting together a modular system for my Nimble Nomad. Check this out. seawaterpro.com. They sell the whole thing for $1595.00. or make your own. They have a video that shows the whole process. The major weakness in his system is using a pressure washer pump for the high pressure pump. They're awfully loud. I'm working on an insulated container for the pump which will be a lot quieter but still allow the required cooling air flow.

Lepke , Ksanders and I have had in-depth discussions on water makers in a different forum. As lepke said they are not rocket science, but the more automated you make it, the more complex the system becomes. This can be both good and bad. Lepke and Ksanders are both very hands on individuals. They would rather keep things simple to maintain. I tend to be a little less sensitive to costs and lean more to the push one button and be done side. Neither of us are wrong. What would be wrong is to buy an automatic system and then complain about the cost of proprietary parts or install a system like Ksanders and fail to understand the necessary procedures to maintain the system.

The right thing to do is to ask more questions.

tiltrider1 said:

Lepke , Ksanders and I have had in-depth discussions on water makers in a different forum. As lepke said they are not rocket science, but the more automated you make it, the more complex the system becomes. This can be both good and bad. Lepke and Ksanders are both very hands on individuals. They would rather keep things simple to maintain. I tend to be a little less sensitive to costs and lean more to the push one button and be done side. Neither of us are wrong. What would be wrong is to buy an automatic system and then complain about the cost of proprietary parts or install a system like Ksanders and fail to understand the necessary procedures to maintain the system.

The right thing to do is to ask more questions.

Click to expand...

Here is a link to the discussion. Folks should read this, it has a lot of great information

https://www.baylinerownersclub.org/...481-water-makers-removing-the-mystery-and-the

Russell Clifton said:

you need to use it at least every 7-10 days......the key word in your post is infrequent user.

Click to expand...

Exactly why I mentioned my cruising habits....for a TF reality check

I frequently make water while underway, out in open water, so to get as clean of water as possible to start with.

Click to expand...

Now I have not heard this recommendation before....makes a lot of sense and will impact my view of the installation. Manufacturers rec a dedicated through-hull b/c the flow is high and could starve another draw on a shared through-hull. My initial thought to save a haul-out and new through-hull was to T off one of the main engines raw water through-hulls b/c I guessed I would be making water when anchored with the engines off. Learned a lot from you on this one....

Also be aware that adjustments are required for sea , fresh and brackish water.

Not the complete story

Russell Clifton said:

Keep in mind that once you start using your watermaker, you need to use it at least every 7-10 days, or else run some chemicals thru it to preserve the membranes. It takes time to do this. Then before you use it again you will need to flush out the chemicals. The key word in your post is infrequent user.

Also, there will be places you do not want to use the watermaker because there is just to many boats in the area or the bay does not flush out well with the tide changes and there is a lot of algae in the water. I frequently make water while underway, out in open water, so to get as clean of water as possible to start with.

Click to expand...

My Spectra backflushes the membrane with fresh water every 120 hours - automatically. Obviates the needs for storage chemicals.

Gordon J said:

My Spectra backflushes the membrane with fresh water every 120 hours - automatically. Obviates the needs for storage chemicals.

Click to expand...

For your model, what is water volume and power consumption per back flush?

A WM is on my list for this Winter. We spend a lot of time at the offshore islands and water rationing has become a pain.

It will see a lot of use, and I am looking at the more automated systems. I also want an AC unit, because I have a large Gen that could use some more load, especially when sitting at anchor or on a mooring ball during the daily house battery charging cycles.

*Spectra has been mentioned a couple times in this thread. I only see DC on their site. Do they make AC units?

*What other AC units do people like?

The Newport series comes in dc or ac. At $17,000 for a 40 g/hr it is not cheap. Smaller units are dc only.

This is a interesting discussion. I work in and “play” in the world of automation a bit.

Lets take the challenge of automating a watermaker and see where this goes.

The first step is to lay out the process of starting up a watermaker, then that will tell us how we could automate that process.

The first thing you do is start the low pressure boost pump. This is a on off switch. This is easy to automate.

Then, after a few seconds you turn on the high pressure pump. This is also a on off switch. This is also easy to automate.

Next you increase the pressure on the membrane by closing a valve in the brine water output. Dow Corning recommends this be done over a period of time, a few minutes to avoid shock loading the membranes and causing premature failure. This is a tough one to automate. You need a electrically driven valve and electronics to measure both pressure and flow through the membranes. Very difficult to automate this step.

Then you need to test the water to make sure it’s low enough TDS. It takes a few minutes for the water to “clear up” and be salt and contaminant free. This is pretty easy to automate. You could use a inline TDS meter with a alarm set point.

Then you need to switch the produced water output from “test” to putting it in your tank. This is pretty easy to automate using solenoid valves.

Shutting the watermaker down is a reverse of that process.

As we can see automating a watermaker to make it a one button system is not all that easy. Yes it can be done, but it’s not a simple process.

The big expensive, difficult part is the pressure valve. That is the hard part.

I’m pretty sure that is where watermaker manufacturers cheat. I’m pretty sure that many “automated” watermakers do not automate the pressure valve.

Yes they are creating the product that their customers want, to be detached from the process, but they are creating problems and inefficiencies.

If you set and forget the pressure valve you are shock loading your membranes. That reduces their lifespan, but probably not enough to have in warranty period claims. It does produce a ready made future corporate profit center though in often proprietary membrane replacements.

If you set and forget your pressure valve you are either overloading the membranes, or you are running your watermaker inefficiently a part of the time.
The reason is that the flow required to get 800PSI through a membrane varies based on the salinity of the water. The salinity of the water varies based on location, and recent rainfall. I have found that a significant local rainfall can reduce my pressure needs to get my rated flow by as much as almost 50%. Location is also key. If I anchor near a stream outflow then the water is less salty, and takes more flow and less pressure to achieve the rated produced water flow.

So... The lesson here is that if you want a automated watermaker with true one button operation, do some research and get on that also automates the pressure valve.

Never wanted a watermaker but since I’ve had one I would be without. Not being hands on plus I’m lazy I want something easy and automatic. I have a Dometic XTC 1800 sea exchange with a spot zero 2000. It cleans itself and when I want to make water I have to decide how many gallons I want to make. I love it, no problems after four years and the water it makes is great. I can wash the boat with it and I don’t need to wipe it down, no spots.