The Offshore Voyaging Reference Site

Q&A: Should I Get a Watermaker?


Member Andreas asks:

This is a great article that highlights some of the decisions I need to make in preparation for casting off on an extended trip this summer. My challenge is balancing cost with usability. The sailboat (SY Baluba) will be used for a 3-year circumnavigation now, but afterwards she will go back to being a weekend warrior as well as seeing plenty of usage in holidays, here in Northern Europe.

A new Spectra Ventura costs a solid chunk of change in Europe. When I spent 2-1/2 years sailing from Norway to Australia seven years ago, I managed fine without a watermaker, but it was a bit of a hassle to always be careful with water usage and never take a fresh water shower (while onboard).

Now I’m planning to sail all the way around, with forays both to the Arctic and Antarctic, so I’m wondering if the watermaker will be a necessary expenditure or if it will be something I’ll get used to being without again? Can I justify spending the money for a unit I’ll need and use a lot for the next three years, knowing that there won’t be much (if any) use for it when I get back to Norway?

What are your thoughts?

John answers:

Hi Andreas,

An interesting question. First off, as I stated in the simplicity post you mention, we don’t have a watermaker, but then we have huge tanks (1000 litres) and generally cruise where water is available reasonably easily and for free.

I think that if your voyage will include the typical tradewind routes I would lean toward installing a watermaker. In many tropical places water is both hard to get and expensive, as you probably already know from your last voyage.

There is another benefit with installing a watermaker and that’s that making your own water substantially reduces the chances of getting a water-borne parasite. And I can tell you, having contracted one from water (ironically in Norway), the resulting illness is no fun at all.

Having said all that, there is one other factor that should go into the decision, and that is your own what I call “optimal simplicity level“: If you are the kind of person who can get by with less in the way of comforts and who also hates mechanical complication, you could certainly get away without a watermaker, particularly if you set up some kind of rain catch system—AAC correspondents Christopher and Molly have managed just fine without a watermaker.

And finally, I would ask yourself “Is a watermaker going to be worth its entire price to me for this voyage only?”.  Watermakers don’t do well on boats that are used intermittently and therefore it will, I suspect, have little value to you once you return to weekend sailing.

In summary, I think that, as so often with boats (life too), there is no right answer, only the answer that is right for you in light of your own complexity- and screwup-tolerance.

If you do go without a watermaker, I strongly suggest a good filtration system.


Does anyone else have any thoughts for Andreas?

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With useful, expensive but non-essential gear like this, I find it helps to convert the cost to a more familiar basis – usually an effective cost per month, like your shore-based bills.

Say the watermaker costs $6,000. It’ll be used for a three-year cruise, and will eat up some consumables – maybe a $200 membrane, a couple of $250 seal kits and six $50 sets of prefilters – during that time.

In my little example, that’s $194 a month, plus some maintenance time, to have fresh water (not unlimited, but enough to generally not worry about running out) for the duration of the cruise.

Is that worth it? Well, again, it’s up to you. For me, that price is too high; I would prefer to fuss around with rainwater collection, have a relatively inexpensive sterilization setup on the drinking water tap, and keep a compact emergency desalinator in the ditch bag. But if low-fuss fresh water is worth $194 a month to you, then by all means, go for it.


I really like your approach. Cost-converting is a good concept, because it tells you exactly how much the piece of kit will cost you. Since I know that I’ll only need the watermaker for 3 years, then it’s easy to break it down, like you did; $194 a month is a high price for water.

The compact emergency desalinators aren’t cheap and in my mind, if I’m spending $1000 for something I’ll hopefully never use, then spending 5 times that amount for something I’ll use daily, is easier to justify. Of course, when it comes to safety equipment we all spend $$$$ on things we’ll hopefully never need.

Marc Dacey

I’ve been mulling this over for some time, as well, particularly as water tanks contribute to our internal ballast of our steel full keeler. We come to the conclusion that “why not both?” is a good answer for us: a modest, simple watermaker to make potable water sufficient for drinking and cooking needs, and rainwater catchment for laundry, washdowns and flushing out the heads. Of course, we are going to be out for five years, minimum, and can be expected to hover in distant lagoons without access to any kind of treated water; this is where a watermaker pays off. I also don’t object, given the sunlight and breeze to make the amps that make the water, to giving away clean water to locals, or trading it to fellow cruisers. So the intention and economics are different, but “watermaker” just sneaks over the line for us of “complication” versus “worth having”. I’ve been influenced, too, by the iffy quality and high price of water in the Caribbean, and therefore clean water is worth the price up front. I would want a modular unit for the purposes of resale or even terrestrial reuse, unless I sold the boat entire when finished cruising. Properly maintained, a good R/O watermaker should last for decades.


You are amortizing the cost over 3 years but it will still have depreciated value since the lifespan of the unit is more than 3 years. The membranes alone can last longer than that.

So let’s say it costs $6k and all in with installation and filters etc it costs $200/month over 3 years. At the end of year 3 you still have a watermaker. Let’s say it’s depreciated to 60% of purchase price (I’m guessing). Your $6k watermaker may now be worth $3600.

So your amortized loss to depreciation over 3 years is $2400. That means while you are spending $200/month your actual true cost is closer to $100/month.

Okay but now remember that if you don’t have a watermaker you will still need to get water. And transport it. Maybe use up gas to drive in early to get it. Your time is worth something. And so on.

Now I’m not saying everyone needs a watermaker. But your math is grossly oversimplified and not representative of reality.

Bill Attwood

We have a Katadyn Power Survivor 40E. Costs much less than a Spectra, is bomb-proof, is an “all-in-one” unit (plus a pre-filter) and produces about 5 liters an hour at a cost of 5.5 amps. Makes the very sensible cost/benefit analysis which Matt gives much more attractive. We haven´t plumbed it in to the water tank, but use it for our daily requirements when under way, filling a plastic container in one of the galley sinks.
Yours aye,


I might be going at it the wrong way, because I’ve always been thinking that getting a hight output watermaker like the Spectra Ventura or (the now discontinued) Katadyn 160E, is better, because then I could run it for a short period per day, but get a lot of water when it did run.
With your solution you always have drinking water and can use the tank water for all other things.
An added bonus by doing it your way is that it is potentially easier to sell the watermaker, or move over into another boat after my 3-year trip is over.
Definitely food for thought.


A smaller one may make sense if let’s say it could run off just renewable and not need a generator. If you have a hydro gen or PV that can run a smaller one as-needed you are basically getting “free” water. You may not have enough juice to run a bigger one off renewables. OTOH if you are running a gas gen for electricity then a bigger one may make more sense.

Plus a smaller one is cheaper and well.. Smaller.

Scott Fraser

John has summed it up pretty well, but let me add two more points.
Another thing to think about is the power source. If you have a generator you can install a bigger (20 +|- gal/hr) unit that runs on AC power. Run the genset an hour a day and you have more water than you need and charged batteries to boot. Without a genset you may need a smaller output 12v system that then requires the main engine to be running or a high output wind or solar system.

Another element in the equation is that seawater temperature has a big impact on output. In the tropics (80 deg F) our 20 yr old system will sometimes produce over 20 gal/hr. In Maine (55 deg?) we get about 12 gal/hr. I imagine in high latitudes the output would be less than 10.

You know the saying: “Everything on a boat involves trade-offs”.


It’s a very good point to keep in mind the power source. I won’t have a generator, so I’ll be using wind and sun to keep my batteries topped up. Running a watermaker can potentially cripple that plan, but I’m looking at how to best solve my energy needs.

Marc Dacey

It’s a question between all your other draws versus your battery capacity and charging capacity and the amount of motorsailing you do. I plan to make water only when I’m motoring by the application of a big alternator; I will have more than enough to keep up with the drawdownm although “between 10 and 2 PM between 20 N and 20 S” should work as well without the engine contribution. I find (to date, because I’m still researching) that a modest draw, modest output watermaker makes more sense for us if we consider separate tanks as I described above: it’s neither hard nor expensive in terms of dollars nor energy to keep a 50 gallon tank of “just drinking water” filled if you have two or three other, similar tanks with rainwater for everything else.

Bob T

Hi all, as John knows I’m pretty passionate about safe, pure, abundant FW aboard and it will show through as I write. I too got a parasite back in the seventies. Mine came from an ice chunk placed in my warm beer in Guatemala. Never again, those bugs stayed around for years. Matt’s cost analysis is good but it lacks two line items, the cost of “suspect” dock water and the cost associated with assuring it is safe. Even catching rain water has a cost associated with it. I place safety above all costs. In most countries with ground water (especially islands) have very hard water, usually >500 ppm dissolved solids and a healthy (or not) dose of disinfectant usually chlorine. It usually isn’t free. Where I cruise its $.30-.50/us gallon and then may not be safe. We make 100% of our FW needs and have since the parasites invaded. We also candle the water (uv filter) allowing us to make water virtually anywhere if you don’t mind cleaning filters. We have a power boat now with all the bells and whistles and use copious amounts of FW FW flushing heads, anchor washdown, 60psi household fixtures) but we have it. The cost is minimal above the capital cost of purchase and installation. If you have a generator a WM is the ideal load, steady and constant. The generator only runs a few hours a day and the WM is on line producing a load and all the FW we could possibly use. We have two units, together producing >80gph. We use washable pre filters and have a convenient set up to rinse the units often. Prior to two years ago we were cruising sailors with a single 20gph unit, again matched our 2-3 hr gen run times. While sailing long legs or anchored the generator ran twice daily for 1.5 hrs each cycle for battery charging and the 60 gal replenishment of the FW. That’s sufficient to rinse down underway and still take showers etc anytime you feel the urge. I’ll assume the question comes from a DC only boat. If so a DC unit is your best option. They are more expensive to purchase indeed but invaluable in my opinion vs dependency on catching rain or trusting suspect municipal water supplies. You are correct, they don’t lie idle well and have little resale value so it’s a three year investment. Regardless of your power source visit Rich, the owner is a cruiser like us with a unit to match any budget. I have used them exclusively for years now. You won’t regret contacting them.


If water safety (parasites, coliform, etc.) is a concern, then I would highly recommend installing a Sterilight S2Q-P-12VDC ultraviolet sterilizer in the potable water line from the tanks to the taps. It draws just 17 watts, costs under $400, requires about 4 minutes and $40 per year of maintenance, and kills *everything*.
I have its larger sibling, the S8Q-PA, in my water system at home. Every water sample we’ve taken to the health department has come back straight zeroes for all biologicals.


We filled our tanks in Panama, before sailing to Galapagos and ended up with water that tasted fine at the dock, but for some reason ended up tasting terrible when we got it in the tanks. Does the Sterilight do anything if you get a batch of bad tasting water?


UV sterilizers just make the water biologically safe, assuming it’s already pretty much free of sediment, heavy metals and other inorganics.

Our home system, which is very similar to what I’d install on a boat, is:
Fresh water source (well/lake on land, water tanks aboard ship).
Filter to 5 microns (removes sediment).
Carbon filter (removes taste/odour).
UV sterilizer (kills pathogens).
Potable water taps.

Even with a watermaker, I’d want this setup. The watermaker outputs safe drinking water, but it doesn’t do anything about pathogens or leachates that might crop up in the storage tanks.


Only towards the end of my trip to Australia, did I install a filter, so I was very lucky and never experienced any parasites. I’m more mindful of it now and it’s one of the two reasons why I’m interested in a watermaker: a steady and safe source of water.
I’ll have a good look at Rich’s site: and weight his options to a more known brand like Katadyn og Spectra. I’ll definitely need a DC system, because I’d like to make do without a generator.

Marc Dacey

I’ve spoken with Rich Boren, and have been impressed with his designs and his logic. His is the sort of DC unit I would consider.

Gene Gruender

We have a powersurvivor 35. Haven’t used it in a few years, but when we were out full time we found it to be invaluable. At about 35 gallons a day, we found it was more than we’d need with one child aboard. When we had guests we had to run it most of the time (non sailors/non cruisers use a lot more water!) but it still provided enough that we could go indefinately without worrying about water. Which brings me to our biggest benefit.

Frequently we’d find a remote place we really liked. We’d have other cruisers we met traveling with us. Usually they’d have no water maker. They were constantly planning around where they might find water next and would have to leave long before they wanted to go in search of expensive, questionable quality water. We’d stay as long as it suited us. It really freed us up to cruise as we’d like.

I have a short list of things I would not leave without, probably in this order.

1. Autopilot
1. Bimini (yes, both #1)
2. Refrigeration
3. Water Maker

There are a lot of other things I’d want, but those are deal breakers.

In 2 years of constant use it never broke down, and still worked each time it laid dormant for a year.


I’ve bought a WindPilot Pacific, so hopefully that will be #1 on my list together with a Bimini.
How long did you run your watermaker per day and what was your power source?

Gene Gruender

We were power hogs, the watermaker was just another item along with 12 volt refrigeration, many lights, x boxes and those toys for the kids. We also made sure we had the brightest anchor light around, and this was before LEDs. It probably was 25 amp hours, but we slept better. So, we probably generated more power than most needed.

We had 4 75 watt solar panels, a small wind generator and a 150 amp alternator. We probably ran the water maker on the average 8 hours or less a day. 10 gallons a day would do us fine, unless we had visitors. Visitors are not so frugal with water, so it usually ran most of the time during a week or so of each visit. We tried to run it when we were either putting power in from solar or the alternator, it’s much more efficient if you don’t have to convert it twice.

There are a lot of watrrmakers around, some trickle like ours, some are like a fire hose. I haven’t heard of any that were just crap, so I think you just have to figure out what suits your situation best.

If you go with 12 volt, you can improve things by spending some time fine tuning your charging systems and storage methods. There has been a lot of information about that subject on this site, and as many opinions on that as there are on watermakers – probably more – so, study it all and give it your best shot.

Gene Gruender

I should mention that when we bought ours they were in a slump and offered the 35 at about $1600, threw in an 06 handheld for free. I see that a 40 is now nearly $4k where ever you buy it and an 80 is only $600 to $1000 more. I really don’t understand how the price got jacked up so much, but if we were starting over today I’d still get a 12 volt unit, but probably grit my teeth pretty bad, cuss a lot and get an 80.


Andreas, this is an interesting decision to have to make. It occurred to me that you could purchase a portable water maker, such as the Rainman – a relatively new product to the market getting some very positive reviews.
When you have finished your circumnavigation you could then sell it.
These systems are very compact and come as a portable (well, about 23kg I think) unit with a built in honda petrol generator, or a unit that can be hooked up to your batteries.


This looks very interesting. For $5500 I’d get a completely standalone unit that can produce 50-70 liters per hour. That price will put it at $153 per month for 3 years, but the beauty of it, would be that it is easy to move over to a new boat and it wouldn’t steal amps from my solar/wind-setup. I would however need to bring more gasoline, but I’ll be bringing that for the outboard anyways…
I’m at work at sea now, where videos are blocked, so I can’t get an idea of how noisy it is. I’ll need to check it out when I get back on land in a few days.

Gerben SYD

I have seen that Rainman in action here in Sydney. It is a very well made unit with quality components. Just as noisy as any portable petrol generator.

Dick Stevenson

Hi Andreas and all,
Agree with Bill about the Katadyne units being bullet-proof and drop dead simple. We have a 160 that is 12 yo. It should be noted that (I believe) the 40 series units have one that is easily convert-able to manual operation. It might, for some, be a safety/redundancy feature that could be appreciated. It is also small and compact and, I would think, be easily sold at the end of 3 years. There is a UK dealer who can re-build/re-furbish older units which is a nice option for those buying used units.
I would lean away from new untested brands/designs. If push comes to shove, I would opt for a tried and true WM unit powered by a Honda gasoline/petrol generator rather than a hybrid unit.
My best, Dick Stevenson

Bill Balme

While I agree that simple is better and therefore having a watermaker goes against that principal, in my case, harmony trumps simple! The Admiral wants water without restriction – so she has it! We have a 40gph unit that runs off our 220V generator – so while we’re making water, we’re charging batteries to top up what the solar, wind and engine missed. We don’t like running the generator for more than an hour a day, but that keeps up topped up on the essentials – and the Admiral is happy! A happy and comfortable boat means we’ll be sailing for longer! 🙂


I want to thank everyone for their great comments! This is really helping!

Both the Katadyn and Spectra units appear to have a good reputation … They are the “same” company (which is why they stopped producing the Katadyn 160, so that sales wouldn’t interfere with the Spectra Ventura), so I hope they will continue to make bullet-proof watermakers.

There’s a lot of support here for getting a watermaker and I’m starting to lean in that direction myself. It does seem like a lot of people have generators, which I’d like to steer clear of, except for maybe a small portable Honda. The power source quickly dictates what sort of watermaker you can use without destroying your power scheme.

In my case I could go for a small unit, like the Katadyn 40, which I’d run off the battery bank (charged by wind/sun), or I’d set up a high output system, where I’d run it off an external power source, like the portable Honda generator, or I’d buy a Rainman.

The Katadyn 40 can be used both electric and manual, which is a very nice feature. It produces 5 liters an hour, which isn’t enough to keep up with a few people showering daily, but it will keep us supplied with drinking water. In this case I’d need to install a filter, like the Sterilight Matt recommended, because I’d still be dependent on topping up my tanks in port along the way.

The problem I see with the more “traditional” watermakers is that you need to get the through-hulls in place, which increases the cost of the system and makes it less likely that you will pull it out to sell it afterwards.

A system like the Rainman removes that problem, but then I’d need to pull it out when I want to make water and have to deal with the noise. It will however have no draw on my batteries and I will need no new through-hulls (so zero $$$ in installation cost). It produces 50-70 liters an hour (at least 10 times as much as the Katadyn 40 and twice as much as the Spectra Ventura), so I’d need to use it much less than the other two. It’s also easier to take to someone for servicing and selling it is also no problem, since it’s not bolted in place. This is of course assuming there is a market for selling it in 3 years.

It’s not great to be an early adopter of a product when you’re setting sail into areas with little, to no facilities. A positive note about the people behind Rainman is that since Andy tipped me about them, I’ve already written them and received a lengthy reply, so their customer support seems excellent.
Katadyn also responded promptly, so I feel like they both focus on their customers.

Dick Stevenson

Hi Andreas and all,
This info may be dated, but maybe others can confirm or negate it.
Years ago, on a different boat, I was devising a nifty set up to store my outboard in a deep stern sail locker (to protect it from the elements and from thievery). A friend who was a surveyor stopped by and commented that this arrangement would negate my insurance policy. He said, were I to make a claim and he was the surveyor, he would be obligated to report it even if the claim had nothing to do with the outboard storage arrangement. The issue was: no gasoline, gas powered machinery, or gas storage containers below or where they could spill into the bilge. Running the tank dry was not an exception, nor were empty containers.
There is certainly an amount of common sense in this, but it is also the kind of thing that could trip up even a safe sailor.
Andreas, you might consider checking with your insurance company on their policies in the regard if planning the gas powered watermaker and you plan to stow between uses below-decks. The same could go for a gas powered genset like Honda.
My best, Dick Stevenson, s/v Alchemy

Gerben SYD

Thank you Dick, this is great comment in this context and it is still valid. I called my insurance company and their expert told me that any fuel (petrol/LPG) containing items or systems must be kept in well ventilated compartments, allowing both spills and vapours to go overboard and not into the bilge (Doh!). Failing to do so would constitute “gross negligence”. So the OB/WM/gen/petrol must be stored in the appropriately ventilated lazarette.

Marc Hall

Particularly for a DC powered unit you should be considering the ratio of gallons of water produced/Amp Hour.

How many gallons of water per amp hour with the Katadyn 40 vs
the Spectra Ventura. The Spectras are more efficient meaning more water for each amp-hour.

Other factors to consider are the number of hours/week you will need to run the water maker and how noisy is it.
In the past I had a Pur (now Katadyn) 80 on the boat. We used about 60 gallons of water per week. The PUR 80 may about ~80 gallons per 24 hours, but made suffcient amount of noise that no one wanted to be on the boat while at anchor when it ran, we normally ran it for several hours each day or every other day.
The energy balance of the boat was such that we never needed to start the engine to balance the energy needs when we were not running the water-maker. Once we started to run the watermaker then those amp-hours primarily needed to be replaced by the running the diesel engine/alternator. After the refit am hoping that the energy balance shifts to support running the water-maker without having to run the engine. Converting all lights to LED and improved refrigerator insulation should help with this as well as moving to a more efficient watermaker.
On the refit of the boat I am looking at one of the Spectra Units. Would generate water at ~half the energy cost in about half the time using a Ventura 150 as a model and makes less noise.

Marc Hall

Bill Wakefield

Hi Andreas,

You have received a lot of good feedback already.

I wanted to mention our boat came with an older Spectra water maker [Santa Cruz model] and it has been a stellar performer. We are currently boating in cooler water (10-12C) at 56N and it produces 45 liters/hr (12 GPH) consuming approximately 0.32 12VDC Amp-Hours/liter (1.2 AH/US Gallon). [All well within rated specs and capacities.]

The Clark pump used in Spectra water makers is very efficient [on 12VDC] in addition to being very quiet (although the 2 feed water pumps on our system are not…)

We have a reasonable amount of potable water storage (833 liters; 220 US Gallons) so we only need to run the water maker occasionally, and then for longer periods of time- which is preferred per the manufacturer.

Of course since we can make water, we more readily justified another non-essential piece of equipment: a vented clothes washer/dryer.

It seems the path of complication/justification/rationalization is a slippery one (for us at least…) We wouldn’t choose to do without either of these conveniences. However, we can do without them as neither is essential…

Stein Varjord

Hi Andreas and all.

I have very little experience with watermakers, but find this discussion interesting in general and a lot of the comments are obviously good thinking.

An efficient watermaker is of course important for a system run from solar panels etc. I would strongly prefer to avoid a generator too. The Spectra appears to give in the region of twice as much water per Amp hour, if I understand it right. Great of course. I have heard complaints that their parts are not easy to get hold of in the more remote corners of the world and that they are very expensive. Might be just rumors. I don’t know.

There might be one more side of the efficiency calculation: How the energy is transferred to the watermaker. I assume most have an electric motor running the pumps. It seems like the Rainman watermaker with a Honda engine is running the pump straight off the engine. Thus it should be a much more efficient energy transfer? A generator engine running an alternator, running an electric motor, running a pump, is too many energy transitions. Must loose a lot of energy. Maybe enough to offset the higher efficiency of the Spectra Watermaker unit?

If so, the direct drive petrol WM might be a good option energy wise, if you can cope with the noise and the hassle of lugging it around…. On the other hand, it should be possible to run a Spectra type setup more directly too, if you do want to run a petrol engine for the WM anyway?

There is an Italian producer that apparently uses a similar system as Spectra and claims same efficiency, but maybe a bit lower prices. They have some followers in the racing community as they use carbon fibre etc. No corrosion, low weight, claiming long life and reliability.

I believe my ideal watermaker should have quite small capacity. For drinking water mostly. Guests that need to shower every day can stay ashore. For me low weight is essential. I’d like it to run from the batteries only, and mostly charge them by solar power etc. No generator. LiFePo batteries increase charge efficiency much, so maybe the numbers work out? A manual mode seems attractive, but I guess it’s heavy work so your increased thirst might equal the water you make…. 🙂

Bill Attwood

One point which is worth making is that watermakers like to be used. This was one of the factors which decided me to buy the Power Survivor. The other was the small size and easy installation. With its production of approx 5 liters per hour ( and 5 to 5.5 amp-hours) we can use it every day. We also practice water discipline, with foot pumps only, sponge baths once a week when under way and using seawater in the galley as much as possible, so we can manage well with 5 liters a day for two of us. Drinking is supplemented by fruit juices and longlife milk in Tetrapacks. I am not sure what we would do with the volume of water produced by one of the larger models, and we should certainly have a problem with the amount of current used.
The manual mode on the Power Survivor is of no use to us – there is no way that we could operate the lever in the space where the watermaker is installed. I also understand from talking to some racing sailors that it is extremely taxing to operate the lever – and these guys were gorillas!


How noisy is the Katadyn 40?
In terms of the manual mode on the unit, I see an excellent opportunity to incorporate it into a work-out routine 😉 Something tells me that if I have no power, I won’t be in a happy exercise mode!

Roger Harris

Hello Andreas,

Personally, I’d suggest not bothering with a watermaker. But if you absolutely must fit one, my own preference would be for Dessalator® over Spectra … IMO the build quality is superior.

Regards, Roger


I checked out the Dessalator (, but if I read the specs right, they use 370 watts to make 30 liters per hour, which on a 12 volt system is 30,8 amps. That’s a power hungry system, compared to the 9 amps the Spectra Ventura uses to make 24 liters an hour. On top of that the Ventura sells for €5723,- while the Dessalator sells for €6505,- (both prices without tax). For me, the Spectra represents a better buy, even though the Dessalator might be of a superior build quality, because I’d want the cheaper and less power hungry system.


Hello everyone,

Thank you again for some very informative comments. Though I was initially quite smitten by the Rainman system, John’s comment was a wake up call. All I had to do was think back to some rough sailing this summer, where the chances of pulling a generator out on deck would be zero.

Dick’s comment about gasoline storage in a hatch or locker was something I absolutely hadn’t thought about, so I’ve contacted my insurance company, to see what they say.

I’m leaning towards either the Katadyn 40 or the Spectra Ventura (I’m also looking into the Schenker unit Stein recommended). It comes down to how I want to sail: If I have the Katadyn it would make my drinking water, but if I had the Spectra, it would make all my water. Price wise the Spectra is €5723, while the Katadyn is €2769 (both prices without tax, purchased in Germany). The question I need to ask myself is if paying an extra €2000 is worth not having to fill water in port and always having clean drinkable water on my tanks.

Following Marc’s advice:
Spectra: 2,6 liters per amp hour.
Katadyn: 1 liter per amp hour.
The Spectra definitely gives more bang for the buck.

Do the Spectra Ventura and the Katadyn 40 generate the same amount of noise when they are in operation, or are they different?
Is it possible to hook either watermaker up to through-hulls already in use (and in place), or do they need their own?

When I first asked John for advice, it was because I was torn whether it was worth buying a watermaker when I knew it would only be used for three years. I’ve come to the conclusion that yes, it is worth it, based on where I’m sailing. Like Gene said, I don’t want to have to leave a beautiful anchorage, because I’m short on water and I don’t want to plan my stops based on where I can find water. Self sufficiency has a hefty price-tag, but in the end I think it’ll be worth it. I’m also going to look up the dealer Dick mentioned to see if a unit can be bought second hand and to see how selling one will work after the trip.

Stein Varjord

Hi Andreas

As mentioned I have just a little experience with this topic, but I have the impression that the Spectra is considerably quieter than most normal brands. According to some people I have spoken to, the Schenker is almost soundless and makes no vibrations. As opposed to all normal watermakers, it has no high-pressure pump but an energy recovery system. I would guess that it’s working principles are similar to the Spectra models and their sound levels probably too, but I haven’t listened to them myself.

Inspired by your comparison between the Spectra and Katadyn units, I looked at the data for the smallest Schenker model, the Schenker Smart 30 basic, rated at 30 liters per hour, then using 110 watt /9 amp hours at 12 V. That I translate to 0,3 Amps per liter, which seems to rip the pants off the two others, but maybe my calculation is flawed? I’m certainly no electric engineer, so I may have calculated wrong.

Its total weight is 25 kilos, which is very good compared to others I’ve looked at, but I really don’t know this market well. I also didn’t look for a price for this model, but they are rumored to be slightly cheaper than Spectra.


Hei Stein,
You switched the numbers in your calculation, so they turn out like this:
Schenker Smart 30 basic: 3,3 liters per Amp Hour
Spectra Ventura: 2,6 liters per Amp Hour.
Katadyn 40: 1 liter per Amp Hour.
The Schenker still comes out more favourably, but I’m not that familiar with the brand, which is something I need to take into consideration. It looks like an excellent unit! I’m waiting for an answer to my price inquiry to them, but from what I can find, it is cheaper than the Spectra.

Stein Varjord

Hi Andreas
That was a silly mistake I made, but at least the calc wasn’t wrong. I just calculated a not so useful answer. 🙂

I stumbled on another Italian manufacturer of water makers that claims to use energy recovery too. HP High Pressure. The company has existed for 70 years and made water makers more than 20 years. Claim to have invented much of the tech other makers use. Maybe true?

I also read a bit about what the energy recovery is about. How it works. The membranes responsible for the reverse osmosis process are basically the same for all water makers. Just a few companies worldwide make the polymers needed. The main difference between the different water maker brands is how they get enough pressure on the sea water to push it through the membrane through molecule sized openings.

The obvious way is to just use a high pressure pump, which is what most water makers do. However, most (>80%) of the sea water pushed into the membrane chamber will not go through the membrane but just pass along the “dirty” side of it and be spilled back into the sea, a bit saltier than before. This is called brine.

When the brine exits the membrane chamber, it still has amost all the pressure needed for the reverse osmosis process. Some energy recovery systems use a turbine to harvest this energy and add pressure on the entering sea water.

This helps efficiency of the system, but the “Clark Pump” is a very much more efficient method. It’s a quite simple and slow moving unit. Completely mechanical. My hunch would be that it’s at least as reliable as a high pressure pump. Probably much longer lasting.

Both Spectra and Schenker use this method. Maybe others too. Schenker seem to have developped a more rigid system without O-rings etc in the moving parts and lower friction from “nano materials”. No parts that will wear out frequently and no parts that will corrode. Don’t take me as a witness for this though. I only repeat what I read.

The Clark Pump works by two pistons connected bu a straight rod and some valves and tubing. It keeps the high pressure system in a semi closed loop and uses the hydraulic principle to amplify the pressure from the feed pump about 10 times. The key is the displacement of the rod connecting the two pistons… That volume is the amount of clean water made per stroke. An attractively simple system.

As for quiet operation of the unit, there is only a normal low pressure feed pump, probably impeller type mostly, and the Clark pump that are the moving parts. The feed pump should be very quiet. The Clark pump seems to use about 5 seconds per stroke, probably depending on model. Each direction shift (every 5 sec or so) seems to make a soft “thump”. Rather quiet, but it can be heard, unless the installation is well sound insulated. A normal water maker makes a motor sound. Considerably more noisy, but also tolerable.

The main trouble with most water makers as I see it, is the energy to run it. Most of them do need a generator or an engine to run them. Then most of the noise, and other disturbances like exhaust and vibrations, come from the energy source. With an extremely much more efficient water maker, it’s fine to run it entirely from solar power etc. That makes the choice easy for me. If I can’t afford something like the Shenker etc, I will not have a water maker, but if I can afford it, I definitely want it.

Stein Varjord

Hi again all.
I’ve been reading some on this topic now, so sorry for spamming you…. 🙂

There seems to be several producers claiming to use energy recovery systems that recycle the brine. It’s not easy to decide how most of them are working, but I have a hunch that most of them use the same principles as in the Clark Pump, which isn’t really a pump but rather a hydraulic pressure amplifier.

One more producer is Eco-Sistems from Barcelona, Spain. They seem to make nice stuff. I had not heard of them before now though. Their model with a similar capacity to the ones previously compared here is this one:
The say average energy consumption is 6,4 watt hours pr liter of water at 12 V. It seems quite good, but it’s not the liters per 1 amp hour previously listed. Someone here will be able to twist the numbers so we can compare…

Another producer is Sea Recovery from California, USA. This is a well-known brand, but most of their water makers are of the normal ones without energy recovery. They do have one with it though, the Ultra Whisper. The smallest one makes 32 liters per hour, so it’s comparable to the other ones mentioned. It’s weight is 59 kilos, which is bad compared to the 25-kilo carbon fiber Schenker. Weights may be not all parts inclusive, though, so probably worth investigating. I didn’t find any consumption data, but it is most likely using a Clark Pump method too, so I assume it’s comparable. This company has a large dealer network, which can be useful.

While reading, I’ve noticed that in addition to normal particle filters, it’s important to have an oil separating filter on the salt water intake as oil will destroy the membrane. Equally, there must be a coal filter between the fresh water tank and the membrane. This removes any chlorine added to the tank when the water maker reverses the flow to rinse the membrane. The Reverse Osmosis supposedly does remove bacteria and virus, but several recommend still having an ultraviolet light cleaning system on the drinking water tap to kill off infections originating in the tank and possible minute failures in the osmosis process.

Some producers (maybe most) also have automatic rinsing sequences and some have various membrane preservation methods. This includes electric charge. Some membranes still in use are more than 10 years old, but membrane life expectancy should be around 5 years it seems. Much shorter if they are mistreated. The various filters should be changed more often.


I’ve looked closer at Schenker Smart 30 and the Spectra Ventura and they have a lot in common. The principles they use to get the 56 BAR of pressure needed to make water is much the same. The differences are: Spectra uses the built in pressure switch on the Shurflo pump, while Schenker has an external, purpose built pressure switch. Schenker found that the little pressure switch on the pump, wasn’t durable enough for the constant cycling of the pump.

You (Stein) mentioned the other big difference: Inside both the Schenker & Spectra are pistons and rods that pass through 16 different O-rings. These have always been a weak point and prone to needing replacing after a few hundred hours. Schenker have encapsulated all of these dynamic O-rings in a plastic material so that they don’t come into contact with the rods.
According to Jim MacDonald at Mactra, after Schenker changed to the dynamic O-rings, they have not had to replace O-rings in any Schenker watermaker they’ve sold.

The Schenker is starting to sound like a good choice.

The Eco Sistems watermaker you mention comes in at:
1,9 liters per Amp Hour, so worse than both the Spectra and Schenker.

Here is a link with some 12v systems currently out there:

The Sea Recovery unit you mention seems like a nice unit, but comes with a hefty price tag.

Stein Varjord

Hi ANdreas.

I’m not shopping for a watermaker now, but I’ve also been reading quite a bit around and have the feeling that Shenker seems pretty good quality and also gives the best performance figures, while still being ok on price, for it’s level of tech.

This type impression is sometimes correct, but I’ve sometimes had good use of asking the competition straight out. “Look. I look at product X and it seems to be the best for me because of…… Is there something I’ve missed? Is your product still better for some reason I don’t know? Can you enlighten me?”

Some producers make this into a silly sales defence, which makes me sure my impression was correct. Some say I am actually correct, which gives me a good feel for both companies. Most educate me in topics I didn’t quite see, which is of course great!

Ron Schroeder

Ron from Rainman here. As there is a bit of discussion relating to Rainman in this thread, I thought it worth while to add a few comments. I’ll try to address various points that have been brought up:

First of all, I don’t think you’ll go wrong with any of the brands mentioned in this thread. They all have good reputations. All use similar reverse osmosis technology, just with their own twist on how to feed pressurised seawater to the membranes.

Output – There are several references to our 50-70lph output. However, our most popular model is the 100-140lph, which costs only slightly more. Both versions of RO case will consume the same energy, so the vast majority of customers go with the high output 100-140lph model. Customers will prefer the compact and lower output model if they are space constrained on a smaller boat.

Petrol or Electric – There is reference for both petrol and electric versions of Rainman. We make both petrol and AC electric (115V/60Hz and 230V/50Hz). Both have their pros and cons, but we make about twice as many electric systems as petrol systems. Rainman does not offer a 12VDC system at this time.

Energy efficiency of the petrol version – The reason we get by with such a small 50cc 4 stroke Honda motor is that we have belt driven directly from the motor to the lift pump and high pressure pumps. We avoid losses related to conversion between mechanical and electrical energy. Our system has a 700ml tank, which will run about 70 minutes. With a few minutes of “overhead” in starting and flushing the system, that will give you about an hour of productive water making. This means 100-140 litres per 700ml of petrol.

Pre-filters – Traditional watermakers will have a 20 micron and 5 micron pre-filter in series. Rainman goes straight to a 5 micron filter. Our feeling is that traditional watermakers are installed out of sight and out of mind, so changing pre-filters will be done less often. Since our system is readily available or brought out on deck, it is a simpler job to change. We capture as much sediment as two filters. Effectively you change one filter twice as often with Rainman, as opposed to two filters half as often with traditional systems. For land based customers that will be running unattended for longer periods of time, we have done modifications to the system to support dual pre-filters. However, for marine applications, we believe this is not necessary.

Running off batteries – There is a comment about our electric system running off battery bank. While this can be done, we recommend it only for emergency backup. The main source of electricity should be a genset. Our electric system is designed using simple General Pump WM series plunger pump, as opposed to energy recovery pumps. It consumes just under 1300 watts, which would be about 110 amps on a 12VDC system. We wanted to keep the system lower cost and lower maintenance, with the trade off of energy recovery.

Using while underway – We originally positioned our system as “portable”, but after seeing about 50% of our customers partially or fully installing their Rainman system, we have now shifted to “installation optional”. People use our system as portable while underway in light seas. There is a discussion thread that goes into this topic ( Alternatively, plumb in the intake hose to make life easier. Many customers with our electric version never pull the pressure unit out on deck, preferring to just run it from down below.

Sound level of petrol version – We have done testing of our petrol system against a Honda 2KVA system running in non-eco mode. From straight in front, we are 2db louder than the Honda, while from 90 degrees to the side, we are 1db softer. As such, it would be fair to say our system is about the same volume as a Honda 2KVA. Our motor is smaller, but the HP pump adds a bit of sound.

Watermaker economics – I like the analysis of breaking the cost into a weekly or monthly basis. However, one point that was ignored is the resale value after the trip. We’ve now had a few customers do their “trip of a lifetime” with a Rainman and then sell the unit afterwards, achieving reasonable recovery of their investment. Granted they were not three years trips, but six or nine month trips. I believe Rainman’s design positions us well for a resale after the trip.

Petrol storage – You definitely need to store the petrol safely. It’s similar issues to consider as with a portable generator or fuel for an outboard motor.

“Relatively new” – Rainman was launched early 2014, so definitely still relatively new. Everyone has their own definition of “early adopter”, but I am hoping most people will think we are beyond the “early adoption” stage. Also, all our key components have been around quite a while. Honda GXH50 motor is the same motor as their 1KVA genset, Filmtec RO membrane, General Pump WM series HP pump, Jabsco lift pump, etc. We’re really just packaging it in a compact format.

Stein Varjord

Hi Ron
Thanks for your clear and thorough comment. Getting the info from the most knowledgeable source is great! This also is a good illustration of why Attainable Adventure Cruising is such a good spot for real info.

Ron Schroeder

For anyone who may still be looking at this thread, I thought it worth while to provide an update about the Rainman system. When I originally posted this, we did not have a 12VDC system available. However, we launched our 12VDC unit a couple months ago and we are happy at how it’s getting received by customers.

It draws 32 amps, including the integrated boost pump, with an output of about 30 lph. When we were debating on whether to use an energy recovery pump, we spoke to many many of our dealers and customers. About 80% of people we spoke with indicated they would prefer keeping with a simple and highly reliable pump, realising this sacrifices some efficiency. The thoughts are that with the technology and price point advances in solar, wind, and batteries, they are less worried about squeezing every drop of water out of each amp-hour.

As such, we decided to keep our design with the very simple and reliable General Pump plunger pump. This design stays with our principles of retaining modest initial price, maximum reliability, and decreased lifecycle cost.

Marc Dacey

I appreciate this description as a watermaker is in our future. The only place I had heard of it was here at AAC.

Rob Gill

Hi Andreas and John,
Thanks for starting this extremely interesting thread on water makers. I have been reading the updates each day with great interest as I am going through the same thought process for a 6 month voyage to the S Pacific in 2017. Like Andreas, we don’t need a water maker for cruising our home waters.
From the discussion, the water coming out on the supply side has been described in a few places as “close to distilled water”. If so will it lack vital minerals? And then, do water-maker owners take mineral tablets, or add dissolvable minerals to their tanks/taps feeds for taste and long term health benefits? Or is this a maritime myth?
Kind regards,

Drew Frye

No, not urban legend. For years I had assumed it was nonsense, but then in the process of researching a series of 4 articles on safe drinking water for a sailing magazine, I learned that it is based in broadly accepted good science. Strangely, taking supplements does not solve the problem, and the risks though quite low, are serious ones that anecdotal success stories do not refute (stroke and heart attack). Not wanting to fall victim to “Lazy Thinking”, here is the support for you to examine.

The moral is that cruisers should drink shore water when they can, assuming rain is probably deficient as well. Seasoning with seawater should help. If water=borne illnesses are a concern, be aware that WHO and the EPA do NOT consider ROs to be effective barriers, though since they run on seawater they are quite safe. On the other hand, an NSF 53-cerified filter system plus chlorine is very safe and <$30.


I work on big ships 6 months of the year, where we get water from evaporators and/or big RO units. They’ve never added minerals to the water on any of the ships I’ve been on. I’ve spoken to several Chief Engineers and they’ve always claimed that you don’t need it. I’ve never fully trusted them, but haven’t suffered any debilitating side-effects from not drinking tap water.

The WHO is obviously no friend to our RO units.

I looked a bit further and found an article that drew the following conclusion:
“Water filtered or treated by RO is pure, clean, and healthy. RO treatment system is currently the only technology that can remove most of the emerging contaminants (i.e., prescription drugs and perchlorate) including other contaminants (i.e., Arsenic, Cyanide, and Fluoride) that are difficult to remove by other treatment methods. No more ingesting of harmful inorganic minerals means the body will no longer be stressed with trying to absorb something that wasn’t supposed to be there in the first place (Wise, 2011). Consumers should not be concerned about the removal of minerals by RO system. WHO (2009) and WQA (2011) pointed out, that the human body obtains vast majority of minerals from food or supplements, not from drinking water.”

I also found this article enlightening:
“Removing these essential elements from our drinking water doesn’t pose much of a problem, since a well-rounded diet will provide these as well.”

This is what I think is the key point: As long as we have a proper diet, drinking RO water won’t be a problem.

Drinking tap water isn’t all that it’s made up to be either, according to this article from the New York Times, that looks at the quality of drinking water in the US:
This article from the Huffington Post basically says that RO water is as good as it gets:

Here in Norway we live under the illusion that our tap water is clean and safe, but as John mentioned the one place he got a water-borne parasite was in Norway. If countries like ours struggle with the quality of tap water, there is little reason to think it will be better elsewhere.

Nothing is ever simple is it?


I just read another WHO study (from 2006), that in many ways vindicates the use of watermakers.

On page 90, under “3.5.3 Dietary supplementation” :
“The geographic distribution of the nutrients in source waters used for drinking water production will be varied and inconsistent so an appropriate diet should be the principal source. In general, drinking water should not be relied upon as a major contributor of significant trace nutrients to daily intake.”

Dick Stevenson

Hi Rob,
My info is a decade old, but we researched this when we were using RO water exclusively in Central America. We decided our regimen of taking a daily multi-vitamin sufficed and found no reason to think different over the 2 winters we spent there.
My best, Dick Stevenson

Stein Varjord

Hi Rob.

Yes, the reverse osmosis process removes most of the minerals. Salt is a mineral. Some remain, but not enough to give you a full supply. On the other hand, that is also almost as true if you drink “mineral water”. Some such waters may contain enough of a mineral or two to satisfy your need, but most of our minerals etc comes with the food.

The myth about mineral water being almost like medicine, comes from the wish to sell bottles of water. Coca Cola was initially also sold as a health product…. Some claim that minerals resolved in water is easier for the body to absorb, but this might also be just unsupported claims.

The water from reverse osmosis has very little or no taste, which is why it’s mostly perceived as tasting very nice. Some minerals improve the taste of water, so it might be nice to add some. That might also contribute to your supply of useful minerals of course. 🙂

Rob Gill

Another question sorry:
I have heard tell of cruisers in the tropics filling their tanks in minutes with effective rain collection. Even if Andreas and ourselves do buy and fit a water-maker, we presumably could save large amounts of power (solar and alternator in our case) by effective rain collection. The deck is the largest catchment on a yacht, and on ours we have solid 4″ gunwales which run-off over the quarter on each side (there are two deck drains that can be easily plugged with a rubber bung).
I have thought about making two sand bags to dam the aft deck run-off and open the in-deck filler caps (after a suitable period to allow the salt to be washed off). Does anyone have experience of similar water collection methods / pitfalls, and how much could we expect to supplement our supply by?

Dick Stevenson

Hi Rob,
We did this effectively in areas with periodic hard rainfalls. We did the same as you are anticipating using led dive weight bags with some towels to direct the whole deck into the deck fill. It is amazing how fast the tanks can be filled to overflowing, which is ok as the bilge can always benefit from some fresh water out of the overflow hose. We bunched some plastic screening in to a ball and had it in the fill tube as a rudimentary coarse filter, but it was usually clean. Luckily the areas with clean rain are places where clean land water is harder to come by while the places with “dirty” rain are often in places where good water is easy to find.
Dick Stevenson, s/v Alchemy

Dick Stevenson

Ps. I suspect there is no need whatsoever to apologize for good questions such as you are asking. Or really, for any question that is asked in good faith. Dick

Bill Wakefield

Regarding ongoing consumption of ‘demineralized’ [or reduced mineral in our case] water:

Background: Output from our Spectra water maker consistently tests below 100ppm [parts per million] TDS [Total Dissolved Solids] with an occasional spike approaching 150ppm- which I attribute to testing too soon after initiating water production. [This from a membrane that is 9+ years old…]

For relative comparison, anything under 500ppm is considered potable [per the manufactures of the two different TDS meters we own] and under 100ppm is suitable for topping-up wet cell lead-acid batteries [according to the specs on our Trojan T-105 FLA batteries.]

Standard procedure is to bypass the potable water tanks with the initial product from a water maker. [Not unlike collecting rain water, but for different reasons…] In our case output is only diverted to the tanks after passing [subjective] taste and [calibrated] TDS meter testing- usually within ~5 minutes of start-up.

Subsequent testing of the water coming from the taps [after being stored in the aluminum water tanks] reveals few, if any changes in TDS meter readings and subjective taste testing. However, we still use a .5µ [one-half micron] filter for all water we drink to ameliorate what might be introduced by the tanks and/or plumbing.

So far, this approach has not led to any of the ill effects typically associated with ‘tainted’ water.

Current Resource:
RE: Is it OK to consume water with reduced mineralization on an ongoing basis?

Many of the studies I previously relied upon are somewhat dated [1980s and 90s]. Therefore this question prompted a search for more recent information on this topic- from seemingly qualified sources. In case anyone is interested, I found this book which has a [brief] section on desalinated water and subsequent mineral considerations [both from human health and system maintenance perspectives- regarding land-based, community water production facilities.]

One re-mineralization solution mentioned [and practiced] is to blend some of the [filtered] raw water with the desalinated water to achieve a mineral balance- an interesting consideration. However, I think we will continue to rely on our daily multi-vitamin/mineral supplements and fluoridated toothpaste…

RE: Collecting Rainwater:
Indirectly related to the above is the question about gathering rain water. I have done this in higher latitude waters and the S Pacific with great success on other boats in the past. I always used a ‘tarp’ of some configuration with a low-profile plastic drain fitting in the center.

I would allow the tarp to be rinsed thoroughly before diverting into the water tank(s). [One has to allow for the helpful assistance from the birds with remineralizing one’s potable water, so sterilization and/or filtration is still necessary… especially with regards to avian vectored, water born parasites like giardia…]

I should also mention that rainwater collection is very common practice for remote cabins and homes in the southeast Alaska area where we currently cruise. Most use a rain gutter downspout device that automatically bypass the tanks for the first few mins of rain before diverting the flow to the holding tank(s).

Dick Stevenson

Hi all,
I just read that in the Feb. 2013 issue of Practical Sailor there is an article of a “head to head test of DC watermakers from Spectra and Racor” and tips on installation/maintaining of same. Who knew that Racor, a fine maker of filters, was making a watermaker?
Dick Stevenson, s/v Alchemy

Richard s (s/v lakota)

with my spectra ventura i have learned that impecable installation is key to good performance…scrimping on this will be a good example of penny wise and pound foolish, and this is probably true with other brands as well…be sure your installer is an expert

richard in tampa bay (just back fm bvi – usvi area where the weather was wetter and squallier than usual for this fall time of the year…was sill enjoyable nonetheless)


I had a long chat with the importer of Schenker watermakers today and he said the same thing as you. He also said that ensuring that the power cables are correctly dimensioned is important, as is a short distance from the through-hull to the pump. A correct install will save you a lot of headaches.

Stein Varjord

Hi Andreas.
About qualified installation. I’ve read somewhere that it’s important to put the seawater supply somewhere you will rarely get bubbles. A bubble will stop water production for some minutes, apparently. Frequent bubbles will then be quite a problem, of course.


Following Stein’s advice, I contacted both Schenker and Spectra&Katadyn to see what they said about each other, as well as a couple of vendors that sold both (or all three), to hear what they said.

Schenker said:
“The Spectra Ventura is a good product as well. We believe our units are more reliable thanks to the technology 2.0 introduced in 2013.
This technology eliminates all the dynamic rubber seals of the watermaker, that are the typical weak point of all hydraulic pumps.”

Spectra said:
“As first point yes it’s true Schenker is using a “new” technology o-ring free but is really new to this so there are no feedbacks from the field yet, Schenker has been in trouble on quality for many years as they were just replicating our system without having the specific acknowledge, in the meanwhile we were improving our products in terms of lowering the maintenance and increasing the reliability. Spectra is used by long distance sailing boats, Ocean crossers, Volvo Ocean racers, Clipper Ventures fleet and charter boats .

Our experience goes over the small/ medium marine systems, we are active in Land Base systems and super Yachts systems with unit over 1.500 lt/hr , we are on this technology since 1990

They still have a limited time warranty while we still provide a life-time warranty on the Clark Pump for material failures, even if we are still using o-rings the Clark Pump can go ahead for few thousand hours without needing maintenance (if not a standard fittings check ), as result for a constant research in better materials our pump is now absolutely reliable .

The difference in price is due to different materials used for example (the feed pump head is Industrial grade pump from Shurflo with aluminum support for extensive use) , all cables are anti-corrosion and the units come with all the parts needed for the installation (hoses clamps fittings) beside this you will not buy just a piece of equipment, you will have a real World Wide full support always at your side 24/7

Our 2016 List Price for the Ventura 150 DX will be 5.723,00 € + Vat so not so far from the Smart 30 List price

At the end ….. Katadyn acquired Spectra and not Schenker…..”

One vendor I contacted said:
“I sold Spectra and Schenker units for many years – they are very reliable.
The Spectra units are very expensive and the spares cost VERY expensive so I stopped selling Spectra 2 years ago (I now only sell used Spectra units)”

Another vendor I contacted said:
“There is not much to choose from between Schenker & Spectra. The principle that they use to get the 56 BAR of pressure needed to make water is much the same. Spectra are more expensive than Schenker and in my opinion some of their technology is a bit behind. Both use a Shurflo pump to bring the water into the watermaker.
Spectra use the built in pressure switch on the Shurflo pump whist Schenker have an external purpose built pressure switch. They found that the little pressure switch on the pump, really wasn’t man enough for the constant cycling of the pump and is a weakness. The other big change is that two years ago Schenker brought out what they call 2.0. Inside both the Schenker & Spectra machines are pistons and rods that pass through 16 different o rings. These have always been a weak point and prone to needing replacing after a few hundred hours. Schenker have encapsulated all of these dynamic o-rings in a plastic material so that they don’t come into contact with the rods. Since doing this we have not had to replace o-rings in any Schenker watermaker sold. They have test run them in the factory for 1000’s of hours.”


The conclusion I’m drawing is that Spectra used to be far ahead of the competition, but that it now seems like Schenker has the edge on them. The fact that I can get a Schenker for €2000 less than a Spectra also makes it very attractive to me, especially since reliability seems good now with the Schekers (they struggled a bit in the past) and their spares are cheaper.

Rob Gill

Thanks everyone for your quality responses as always. Bill, thanks for the links – I like your tarp idea. Multi-vitamins sound the way to go and we will have to see about the whole taste thing – I understand adding a drop or two to the whisky is a perfectly “fair and polite” way to drink water!

Drew Frye

Human nutrition is incredibly complex and I find it fascinating that we have not learned everything by now, but we haven’t. I thought the Ro information was worth sharing and I’m glad you all dug into it.

Yes, I’m quite sure that the lack of Mg and Ca (and other trace minerals) in drinking water can be compensated for. However, make sure the multivitamin actually has what you need (many are actually very low in Ca and Mg, since most diets are not deficient). This generic from Walgrens has a whopping 2.5% of the daily requirement and would be a complete waste of time. Most are less than 30%, still not nearly enough for use with RO water. Do the research.

Nutrition Facts
Serving Size : 1 Tablet, Servings per Container : 60
Amount Per Serving % Daily value*
Vitamin A 10,000 IU 200
Vitamin C 100 mg 170
Vitamin D 400 IU 100
Vitamin E 100 IU 330
Thiamin (B1) 15 mg 1000
Riboflavin (B2) 17 mg 1000
Niacin (B3) 20 mg 100
Vitamin B6 17 mg 850
Folate,Folic Acid,Folacin 400 mcg 100
Vitamin B12 50 mcg 830
Biotin 300 mcg 100
Pantothenic acid 50 mg 500
Calcium 25 mg 2.5
Iron 18 mg 100
Iodine 150 mcg 100
Magnesium 10 mg 2.5
Zinc 15 mg 100
Selenium 200 mcg 286
Copper 2 mg 100
Manganese 5 mg 250
Chromium 200 mcg 167
Molybdenum 50 mg 67
Potassium 5 mg
Silicon 10 mg
Vanadium 10 mcg
Boron 3 mg

Geir ove

So if i have a few beers, and a glass of wine, every day, i will get al my vitamins and other stuff that we need, water from the WM normally get used for food and showers.

Bill Wakefield

Hi Drew,

Thanks for reminding us all that we really do need to pay attention [in the long run…] to our nutrition and not to trust our typical supplements to do that for us. [No, I’m not a health nut, but this does remind me of scurvy and rickets…]

To that end, I found some seemingly useful [and succinct] info on the US Nat’l Institute of Health – Office of Dietary Supplements [NIH] website, and have included the links for Calcium and Magnesium below:



Note: The above ‘Factsheets’ have tabs to select the ‘Health Professional’ [linked above] or ‘Consumer’ versions of the info of interest.

Bon Appétit everyone!