Committing to a Watermaker |
This discussion covers the following
topics:
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Why (and when) to install a watermaker: |
Since we've managed very comfortably without a watermaker for 8 years of cruising and in many different venues, it was with some regret that we decided to install one for the Pacific run. When it came to water, life had been simple. Now it was going to get complicated. |
Does one need a watermaker? To back up just a bit, here's my suggested 3-Step method for deciding whether & when to install a watermaker on a cruising boat: |
Step 1:
Go cruising, first.
Give yourselves some time to adapt to the lifestyle and
learn what your water needs are.
This may also allow you a chance to frame your
realistic cruising goals, geographically speaking.
How else will you be able to size the watermaker you may
later purchase...or know whether your future cruising will
mandate a watermaker?
Remember that RO watermakers are sold all over world.
Some cruisers even think the best watermakers are not
readily available in North America but rather in cruising
destinations like Europe and |
Step 2: As your cruising begins, fabricate a good rain collection system for your boat to catch rain water. I would define a “good” system as: 1) it uses the deck (which is large in area, doesn't add windage at anchor, doesn't need to be set up or struck in high winds, and doesn't flap around in the breeze; 2) can be activated from within the boat, perhaps at 3 a.m. when you'd like to remain dry and warm; and 3) filters or screens the water and deposits it in your water tanks with no manual labor on your part. Depending on where you are cruising, such a system may help you only a bit or a great deal (in most places around the world). Such a system is usually simple and inexpensive to arrange, takes no power and minimal maintenance, and might allow you to adjust downward the capacity and therefore cost of any watermaker you may later decide you need. |
Step 3: With some real-world experience on your boat with your crew, you can now consider whether a watermaker is A) needed, B) desired or C) unnecessary. Usually, the answer is B or C. |
How we went from C to A: We'd followed these steps and kept finding that, for us, the answer was C. But now our answer had become A and with a bit of B thrown in; how did that happen? Here are our Pacific cruising-related reasons that led us to install a watermaker: |
1. Crew. All our cruising had been as a crew of two. We were now adding a third crew member to help with the passagemaking. Our 150 gallon water supply had suddenly shrunk by 50% (from 75 gals/person to 50). 2. Availability. We were off to visit many small island communities which depend on catching rain water to supply their needs. In dry periods, these communities may not have water available to share with visitors...or almost as bad, their catchments may be at low levels and so of dubious water quality. (Next chance you have, look inside one of those catchments).
3.
Health.
Some Pacific island communities are not disease free.
Taking on water throughout Europe, the 4. Logistics. No hose bibs and marina docks are in WHOOSH's Pacific future. We expect the normal method for all provisioning will be via bags & jugs while using a dinghy. And altho' this reason definitely falls into the B) category, a watermaker will help us avoid jugging water, which in the Pacific Islands can be a fair savings of labor. |
Which watermakers
did we consider...and why? |
First, the basic criteria: Things started out so logically and simply, you understand. My first criterion was a 12V system, which means I didn't (but you might) consider an engine-driven system (no room inside the engine box) or an AC unit supported by an installed generator (which WHOOSH lacks). I also liked the redundancy a 12V system offers as it can continue to make water via alternative 12V sources and/or a small portable generator we carry, even if the main engine is kaput. So this decision alone quite narrowly focused the rest of our research. |
With the basic criteria firmly (I thought) in hand, I quickly worked my way down to 3 choices: |
1.
The PUR 160, now manufactured by
Katadyn, a Swiss company (www.katadyn.com).
Claimed performance is 6.8 gals/hr at 18 amps (12V DC) or
2.65 amp/hrs per gallon of product water.
Anecdotally, I have heard of many failures of the smaller
PUR 40, even right out of the box or in the first year of use.
But among long distance sailors using the PUR 160, I
heard of far fewer
failures and it is a very simple system, which means
installation is relatively easy.
Checking the SSCA Equipment Survey (on-line with 1500
surveys completed by boat owners in mid-2009), the PUR brand had
the largest installed base in that survey and one of the lowest
failure rates.
Could this be our choice?
One fly in the ointment is that I couldn't find any PUR
owner raving about customer service & support, either over in
Europe or back in the 2. Village Marine's Little Wonder 200 (http://www.villagemarine.com), another 12V modular unit. Claimed performance is 8 gals/hr at 17 amps (12V DC) or 2.1 amp/hrs/ per gallon. Anecdotally, these units consistently got high praise among cruising sailors both for reliability and dealer support. I found this e.g. to be the case among Yahoo user groups (e.g. Pacific Puddle Jumpers group of Pacific cruisers) and among SSCA Discussion Board members. And the SSCA Equipment Survey showed VM units to be the second-largest installed base and with relatively low failure rates. This choice looked even better...
3.
Spectra |
Common Denominators: All three of these units are modular. I spoke to dealers for all three brands and was equally impressed. All three systems will produce less water than claimed in a variety of circumstances, and are unlikely to exceed their ratings at any time. All three are basically 'manual' in operation and omit automatic features, meaning they must be manually back flushed with fresh water or pickled, their filters visually examined and changed, and the unit generally monitored by a thinking, caring owner. |
The missing criterion: At this point and while still mulling choices, it dawned on me I had been so focused on weighing each brand's details that I'd neglected the key criterion. Specifically, how much water did my crew need me to make? And based on that, for each brand how much electricity would need be consumed? And based on that, how far out of whack was each watermaker going to put my DC energy budget. And finally, how was I going to replace those additional consumed amps? I had missed a whopper of a tree while busily analyzing the forest. |
One decision made: And so a basic plan for managing water aboard WHOOSH on her Pacific run had been formed. I would install a Spectra unit, use a tow generator's excess energy while on passage to fill the water tanks and keep the battery bank up, arrive at the next island with full tanks & bank, live off the stored water while replacing the daily DC load with our wind gen and Honda generator, and then depart on the next leg with plans to refill tanks and bank. If the Spectra performs close to its claims, my (hypothetical) numbers work. It will be interesting to see what we experience out in the real world. |
First, let it be said that nothing apparently generates more creativity among boat owners than a modular watermaker that needs installing. I've seen installations that would make a Swiss watchmaker proud. For others, I've had to walk bow to stern to witness the various pieces. Carpets are rolled up and cushions pulled away to reveal a wide array of components. And some units hang upside down, seemingly defying gravity like bats in a cave. The more installations one sees, the more options one gets to choose from when installing one's own unit. |
Second, boats like WHOOSH which have been cruising for a while have a further challenge. Buy a new boat and you might have several choices on where to place the watermaker's components. There might even be room for a frame (non-modular) unit. Cruise a boat for some years – a place for everything and every place filled – and you've got some spatial challenges on your hands, not to mention a really fun install . This is further magnified if living aboard at the time. For WHOOSH, our motto became: Relocate existing 'things' to make room for watermaker 'things'. Said differently, there was a Ripple Effect that expanded the work to be done beyond installing the watermaker. |
Third, don't overlook the fact that a self-contained or 'frame' model will take far fewer man hours to install than a modular unit yet cost very little more. Just be sure to consider how accessible the individual components of a frame model will be, which in turn will depend on the location of your installation. Modular may also be more expensive in the sense that one will need runs of hose, hose clamps, and perhaps fashioning small mounting platforms for some of the modules. In my specific case, with a modular install behind me, I would look extra hard next time at whether a frame modl could be made to work. |
Fourth, and as noted above, the unit you choose will dictate much of how & where the unit will be installed. Depending on the brand chosen, some components must be installed below the waterline, other components not more than X feet above the waterline, while still others must become part of the same temporary loop for flushing with chemicals...so beware installing them at opposite ends of the boat. The pumps and pressure vessels have enough mass that they need to be robustly thru-bolted...to something already there or something you add. You can 'T' the discharge feed water into an existing thru-hull but it's universally recommended that you be able to observe the discharge flow, as it is one way to monitor system performance. It's also uniformly recommended not to 'T' the inlet feed water, which of course means a dedicated thru-hull & valve - somewhere. Another uniform requirement is that the inlet thru-hull needs to be of the scoop type. You might need to leave room above the pump motor for an oil change, or insure things under the pre-filters won't be damaged by salt water when you change filters, and please don't forget the eventual challenge of removing and replacing the membrane or its seals when this is required. Be sure to keep the wire runs short, avoid elbows and kinks in the hoses, and keep your shorts from getting in a twist. There is no shortage of guidelines and constraints. |
Less is more: Since ours is an installation done by a Rookie, I'll offer just a few specific comments on it. You will probably find them related mostly to the Spectra product and perhaps our boat's layout. |
Pleasing Discoveries: There were some pleasing discoveries about installing the Spectra unit. The only wiring required is a single pair of wires from the Feed Pump that only need to carry 10 amps, about 4 wire gauge sizes smaller (for a 3% loss) than what the other two modular systems would have required. West Marine puts that in perspective by noting that going down in wire gauge by 2 (e.g. from 12 to 10 gauge) means the amount of copper in the wire goes up by 59%. A smaller wire gauge (for no more line loss) means an easier wire run. |
Where to put the |
The 'Before' pic of the port sail locker where I'd hoped to install the Clark Pump |
The 'After' pic with Clark Pump thru-bolted to platform but with canister not yet mounted nor hoses run. A Sunbrella 'shower curtain' snaps onto the platform base to shield the Isolation Transformer from any drips |
Where to put the Feed Pump module? Like many Pearson 424 owners, we had previously cut a hole in the outboard shower stall wall and installed a watertight locker door behind which we stow various bulky items. This area drains directly to the bilge and the DC panel and WHOOSH's main -12V bus are quite near-by, so our wire run could be short. This was the third place I mounted this module, which no doubt is a comment about me but also about the value of having the real hardware in hand. Absent leaks in the hose connections, the charcoal filter on this module only needs changing once every 6 months and the area will only see fresh water drained from the filter canister.
Shower stall with outboard locker shown, soon destined to be the home for... |
...the Feed Pump & fresh water flush module (where the only wire connections are made). This is also one point where pickling hose is attached, the other being at the Clark Pump. |
This busy picture shows several things; let's take them one at a time. The large Y valve (blue handle) is part of a deck collection system that was previously installed and connects the top of the Y valve to a deck drain. The large black (vertical) hose leads from the Y valve, overboard, to the thru-hull. The white (curved) hose leads from the Y valve to the (white) collection box (a Rule off-the-shelf 'shower sump') when collecting rain water off the side deck. A horizontal vinyl tube can be seen in the background, running forward (to the left) from the collection box and toward the tank fills. Because this system was already installed, I just piggy-backed the distribution of the watermakerf's product water to it. The watermaker's grey distribution Y valve can just be seen in the upper right corner of the open locker; it receives product water from the Clark Pump via an output measuring gauge. When 'good' water is being made, the short, curved (and thin) black tube dumps product water from the grey distribution valve into the Rule collection box (and subsequently, the water tanks). A second black tube, longer and normally just coiled inside the locker, runs from the distribution valve into the sink drain or into a glass, where testing and tasting can be done. This would be put in place before the watermaker is turned on. (It can also reach into the shower for bucket filling, if needed) |
Where to put that (Damn!) new thru-hull? No doubt like everyone else who didn't have a dedicated thru-hull available, I fussed and mulled and generally was in denial for some time about adding (yet another!) thru-hull. In the end, I'm sure it was the right choice for WHOOSH and the new scoop thru-hull insures good flow when underway or anchored in a current. (Manufacturers are quick to point out a mushroom-style thru-hull tends to create a small competing vacuum in the line as water flows across its mouth, and in fact not using a scoop-type thru-hull voids some warranties). |
Perhaps the acceptable answer is not to. Here are some things I considered when making that decision: |
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In my case, I only had two potential thru-hull candidates to 'T' off of - my two cockpit scupper drain lines. They failed to satisfy me on almost all of the above criteria, so a new thru-hull became one of our compromises when adding this system. The offsetting benefit is that at least it is located about as ideally as possible. |
The installation was not all sweetness
and light:
While
Spectra's |
So where does the product water go? Ultimately one is rewarded with potable water, so now what? Usually, a distribution valve of some kind – a 'Y' valve – is recommended so that initial product water, still salty, can be discarded and the 'good' stuff tested before the valve is thrown and distribution to the tank(s) can begin. (I saw PUR literature that told the user to only collect product water in jugs and then decant the jugs into a tank via the deck fill after testing each jug's water, as this way salty product water – e.g. if the system had failed while being operated – can never contaminate the potable water in the tank. Tho' good insurance, this doesn't sound too suitable for folks out sailing). Before finalizing your distribution arrangement, here are some things to consider: |
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Considering the above, it's not surprising that many watermaker distribution valves end up in the head (where there is both a sink and a shower stall) or the galley area. We chose the head. Our product water is either sent via a short run of tubing to the sink (or by adding additional tubing, down to the shower stall pan) or, throwing the distribution valve the other way, is distributed into a sealed pan (a Rule product originally intended to serve as a shower sump). From there, the feed water is sent forward to a 'manifold' (just another 'Y' valve) in the forward cabin and finally diverted to either the bow or starboard tank. |
Because there are so many variables involved in the installation and performance of a watermaker, the cost and effort are both significant, and the results (water) so important, choosing a watermaker deserves a fair bit of research. (There's also abundant 'urban legend' re: watermakers, further necessitating fact over hearsay). In that regard, what follows are a few on-line sources that I thought were helpful. Just keep in mind that most products evolve – in design, construction and documentation – and the following references are all historical, meaning things have most likely changed between the time these were written and when you are reading them. |
http://www.hydrovane-watermakers.com/products.html#Mazza This is a collection of watermaker-related articles by some individual cruising folks, including Nigel Calder, and is offered by the Hydrovane dealer who carries the Trinidad-built EchoTec watermaker brand. After the inevitable pitch for the rationale that EchoTec's units operate by, you'll find the write-ups. I especially appreciated the first and the last write-ups. The first, written by Nigel, points to the fact that even 'systems experts' can make some bad (as in 'human') choices in how a watermaker is installed, as well as how the boat is operated when a watermaker is aboard. The moral of the story is not to underestimate the possibility of a 'calamity'. In Nigel's case, it was ending up mid-ocean with a watermaker, two water tanks, and no water. The second (last) article I appreciated not because of the author's “final” conclusion (his latest watermaker is only 6 months old and still on its Honeymoon) but because it chronicles the realities and the history of watermakers on cruising boats. It rarely has been an unblemished and happy story. |
http://www.spectrawatermakers.com/articles/Don_Wilson.html This is a summary of observations and advice by a cruising sailor, Don Wilson of TACKLESS II, who was trained at the Spectra factory so he could also serve as an 'in the field' Spectra service rep. While it is oriented to the Spectra product line, there is a lot of 'real world' information in Don's article that I think any cruising watermaker user would benefit by reading. And isn't it noteworthy how often the problems boil down to the basics: clean feed water, good filter maintenance, a healthy DC voltage at the watermaker, the right operational practices, and paying attention to the details (good installation, addressing drips and such). |
The first link is the front door to the Seven Seas Cruising Association. I offer it here because, if you are a member, you can log in and go directly to the SSCA Equipment Survey where there is a wealth of detail about the systems cruising sailors choose for their boats and anecdotal comments on what has worked, tricks that have been learned, and so forth. This can be very instructive reading and may be worth the cost of membership ($50/year for a crew) all by itself.
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We have only begun to live with our Spectra unit, so allow us to experience it for a while and we'll put our further impressions on both the “honeymoon and also the marriage” here. |
Update as of April, 2010:
We've been using and
living with this watermaker for a few months now and already I
realize there are some additional thoughts worth adding, so
let's consider comments on the marriage's first year. |
Feed Pump Installation:
The sound isolation pads
on the Clark Pump are excellent, yet the unit itself
generates little vibration or noise. The feedpump, on the
other hand, is buzzy noisy and if placed near an area on the
boat you are going to occupy (and what part isn't?), it needs to
be sound isolated. I
used some of the same rubber material that I use to isolate the
wind generator pole from the mizzen mast where they are bolted
together, and this has helped considerably.
I recommend you do NOT just screw the Feed Pump to the
mounting surface as I originally did. |
One vs. Two Pre-Filters? This unit as provided by Spectra came with only a single pre-filter body and 5 micron filters. Since buying it, I've been sternly warned by some (experienced, long-term) Spectra owners that the unit should have two pre-filters, a 20 micron unit ahead of the 5 micron unit like most of the rest of the Spectra line. I've also met cruising folks (and pleased Spectra users) who have been using their units with only the single 5 micron pre-filter. If there's no 'right' answer, what might be the 'better' answer, I've wondered? I notice Don Wilson, in his excellent "Operator's Notes for Cruisers" mentioned earlier, highly recommends two pre-filters for the two feed pump systems because the high volume of water (about 150 gals/hr of feed water) is simply asking an awful lot of one pre-filter. Extending the logic – and recognizing that I've already made water while anchored in Panamanian water I wasn't thrilled about using – that seemed to suggest to me that two pre-filters would, to some degree, add protection to the Clark Pump that otherwise wouldn't exist. On arriving in Colon, Panama I added the second pre-filter housing. It's been interesting to note that the 20 micron filter is collecting noticeably less 'crud' than the 5 micron filter. This has tempered my view that two pre-filters are 'essential'. I think the more important issues are whether one has the tankage (and cruising plans) to restrict watermaking to really clean water (e.g. when at sea) and how diligent one is at replacing filters. |
'Real World' Water Production: As noted earlier, I sprung for the 200T Deluxe unit (over the 150), willingly paying a bit more money and one more amp of DC to obtain two more gals/hr. This seemed like a great trade-off and, to refresh you on the specs, I'm supposed to be seeing 8.3 gals/hr at a water temp of 75º F. I assume this initial experience we're having is going to be our 'best case' for this system, as we've been running it in 80-85º F water, the system is all new, and we've limited watermaking to times when the batteries have been on charge (and so usually at 13V+). I'm usually seeing 9 gals/hr as meaured on the little gauge, but I recently measured actual output (with a scummy 5 micron and clean 20 micron filters) of 8.2 gals/hr for the above operating conditions. So my unit is performing close to spec and the gauge appears to be optimistic by ~ 1 gal/hr. |
'Real World' Electrical Use: Again, the 200T specs promised electrical consumption of 10 amps DC at a (generically labeled) "12V". I have at times run the unit when the batteries are not in charge but with battery voltage relatively high (12.4 – 12.6) and I have never seen 10A DC, usually seeing 9.5 or so. I'm confident the Link 2000R I'm measuring this with is accurate, so perhaps this is an example of a new system showing optimum performance. It is certainly energy efficient. |
Where to Put the Pieces, Chapter 2: I have both my pre-filter cartridges in one of the sail lockers. In many ways, this works nicely. But are your sail lockers like mine? (Think 'long distance cruising boat...). Changing the pre-filters is easily done once I can slip into the locker, but emptying the forward section of the locker is a bit of a hassle, not easily done at sea and probably retards my intent to change filters. I'm just saying... |
Water Consumption: We wondered just how much, if at all, our rate of water consumption would increase once we had a watermaker. On the one hand, we've done a decade of cruising on two boats without one...so we now consume water thoughtfully and our habits are well ingrained. But we also hear from everyone who's made this transition that their consumption rate has increased, sometimes spectacularly. Obviously, some increased consumption is inevitable as some old habits exist within a new context. E.g. when offshore and in secluded anchorages (without knowledge of when we'd next refill our tanks), we would rinse our dishes off with salt water, then wash them with hot soapy salt water, and then spritz them with fresh from a squirt bottle, to spray off the salt before setting them to drain and be dried. We first learned to do this when cruising in the Bahamas and it noticeably reduces how long a tank of water lasts. However, now the washing part of this seems an unnecessary time-consuming step. Instead, we prefer to save the propane, rinse off everything using salt water and do the washing with fresh. But the big surprise for us has been how much more water it seems necessary to use when showering, as the watermaker's water is very soft and removing soap from one's body just inevitably requires more rinsing. Bottom line for us: We used to see, on average and without the salt water dish washing regimen, a usage level of about 7 gals/day. Now it turns out to be about 10 gals/day. So far... |
As you might know, a marriage's first year is not without its trials...and I've had a few laughs at my own expense, as well, flooding a locker because I set a valve incorrectly and over-filling a tank, which also back-flooded that same locker. But in general, it's been an easy 'first year' – so far. |
© Jack Tyler – April, 2010 |