Which Watermaker To Choose

[carstenb]

Hi all,

Before anybody starts, I have searched the threads for this but can't find it so here goes:


I need to buy a watermaker for the boat. We will be going RTW. Basically we will be only tow most of the time but friends will join us and then we'll be four persons. Our boat has 2 x 150 liter tanks total 300 liters (75 gallons or so for you non-metric types).

I'm expecting that the two of us will use between 20 and 30 liters per day. If we say that we will refill whenever the first tank is empty, then we will need to use the watermaker every week or so (might be easier to just run it every other day).

So the smallest watermaker I've found is 20 liters per hour, which sounds small, since we'll end up having to run it and the engine for at least a couple of hours each time.

A 40 liter per hour probably makes more sense.

Now the question: Which water maker?

Lots of them out there - which one is the best value for money?

Advice appreciated

Thanks

[Dulcesuenos]

From what I have read a water maker needs to be pickeled if it sits more than a few days. I would think planning to run it only every week or two would drive you nuts from a pickling standpoint. I purchased a PUR 40e 1.4gallons per hour, so when we cruise or live aboard, plan on running it, for 4-6 hours every 2 days or so. I hear they are much happier this way and grow less nasty stuff in the membrane when used more. I guess youd be fine with your choice and you could get away running it every three days for a few hours vs every 1 or two weeks for much longer. I could be wrong though,,,

[noelex 77]

We have similar requirements to you and purchased a Spectra 150 3 years ago and could not be happier with it, but this may not suit you.

When deciding on a watermaker the first step is t consider how you are going to power it. They use a lot energy.

For a primarily solar powered boat an energy efficient watermaker like a Spectra is a must. It can be quite small and run for two to three hours every second day like we do.
If you get most of your energy from generator or main engine power you need a much larger watermaker that will make enough water during the generator / engine time to make all your water. Energy efficiency is less important.

The cost of a small energy recovery watermaker and a large energy inefficient watermaker is reasonably similar.

The watermaker needs to run at least every 5 days, or it needs pickling, or a freshwater flush.

[Tellie]

I've built a dozen or so watermakers for myself and others and I sell and service several brands as well. I have a soft spot for sailors because I are one. But deciding on which watermaker is the right one for you and your boat takes a bit of consideration and knowing the right questions to ask. Watermakers are expensive and you want to make the right choice that fits your needs and your boats capabilities along with your cruising style. Choose the right one and they are worth their weight in gold. Choose the wrong one and you'll curse them at every Tiki bar you'll stop at. I'm always available and my advice is free, all you have to do is ask.

[Albro359]

We have 2 x 125 litre tanks which are kept full most of the time by our Schenker 35 l/hr watermaker.
We've had it on board for 3 years and wouledn't be without it. Its of the latest generation using waste recovery and a hydraulic amplifier, so the pump only needs to be small. Our system produces 35 l/hr and only consumes 8 amps. It can run from our solar panels on a sunny day.

Agree you need to use them every 2 days and we flush with fresh water after each use...not much only 30 seconds or so keeps everything good.

Pickle it when we go away for extended periods and it takes about an hour of rinsing to clear it and then we're producing sweet water again.

Marvellous...and yes it ws quite expensive, but well worth it !

[Auspicious]

If you're looking at a 12VDC or 24VDC unit you might want to look at efficiency v. capacity. What I have seen is that there is a sweet spot at around 300 gpd (US gallons / day) that minimizes Ah/gal.

[Pete7]

If you do a bit of maths I think all three Katadyns require about 70 amp hours @ 12v to produce 100 litres. The Spectra 150 requires about 35 amp hours, so big difference if you are using solar to charge the batteries and therefore run the water maker.

However, you asked which is the best value for money and that should also depend on cost and space required or available.

Are you sailing anywhere near Jersey? the VAT free price of a Katadyn looks tempting.

Katadyn

Pete

[carstenb]

I'm salng in the Baltic. Germany is nearby, and prices are generally lower there

[Oceansailor]

I would recommend the DML-260 from Echotec. Installed this watermaker 2005 and are extreamly happy. Not one problem.

It produces 50l/h. 12V/40A.

40 A might sond a lot. But as I always run the engine when making water it is not a problem. The company is great to work with.

[svpattyd]

Agree with Oceansailor. The EchoTec is wonderful. Can buy filters easily at retail stores. Components so it was easy to install.

[daddle]

I would rather have a small capacity watermaker that runs often. Not a large capacity unit that runs infrequently. I.e: One that ran at just a few amps all day while the sun was shining rather that one that needs the engine or big battery bank to run just a few hours every few days.

Your usage estimate seems low. Possible, but uncommon I think.

I like guaranteed low TDS. 200-500ppm is too high. Some are vague about their poor performance.

[Cheechako]

I was very satisfied with engine driven units. 20-25 gal per hour. It seems I'm always motoring some, even If I've sailed all day to a destination, usually end up motoring the last hour or so. Or if you have a large alternator, you can charge the batts some and make water... keeping the engine loaded up which is a good thing.

[noelex 77]

Originally Posted by Oceansailor

I would recommend the DML-260 from Echotec. Installed this watermaker 2005 and are extreamly happy. Not one problem.

It produces 50l/h. 12V/40A.

40 A might sond a lot. But as I always run the engine when making water it is not a problem. The company is great to work with.

This shows how you need to think about how you will power the watermaker as a first step.
I live on board the boat permanently and make 95% of my water via the watermaker, but as a sail much more than I motor. I only average 80hrs a year on the motor.
My requirements mean the power consumption of the watermaker are much more important than Oceansailor.
So I have chosen a power recovery watermaker (spectra) while Oceansailors requirements are very different.

[Oceansailor]

Originally Posted by noelex 77

This shows how you need to think about how you will power the watermaker as a first step.
I live on board the boat permanently and make 95% of my water via the watermaker, but as a sail much more than I motor. I only average 80hrs a year on the motor.
My requirements mean the power consumption of the watermaker are much more important than Oceansailor.
So I have chosen a power recovery watermaker (spectra) while Oceansailors requirements are very different.

True!

If your boat is set up for solar or/and wind power and want to avoid engine hours a power recovery watermaker is the right choice.

But if your battery bank, alternator and watertanks are sized accordingly you can save money avoiding a recovery watermaker.

As 90 % of my energy is generated from the engine, I decided 20 or 40Ah does not really matters. Energy has to be replaced by the engine. As the Echotec was half the price compared with a power recovery watermaker, I had money to install a second alternator instead. This means I fill my batteries faster as before the installation of the watermaker. As a bonus I have redundency for the alternators. I have the same engine hours as before the watermaker!

My battery bank is 900 Ah. If I come to an anchorage and the batteries are full, I can run the watermaker whitout the engine for 3 -4 hours. This I do if I will motor next day. Running the engine only for watermaking would be inefficent use of the engine.

Last 6 month of cruising ( full time on the boat ) I had 120 engine hours. During the same time I had 141 hours of watermaker time. ( 7050l of water)

Compared with the recovery models the Echotec is much more basic. No salinity probes etc. Not one sensor in the unit. Belive me that is an advantage in the long run! There is not much that can go wrong on a basic watermaker. The only negative is that the are noisy compared with the recovery models.

My last advice. Buy as much capacity as you can afford from the beginning. Most people I have met say the same thing. "I should have bought a unit with more capacity"

[noelex 77]

Originally Posted by Oceansailor

Compared with the recovery models the Echotec is much more basic. No salinity probes etc. Not one sensor in the unit. Belive me that is an advantage in the long run! There is not much that can go wrong on a basic watermaker. The only negative is that the are noisy compared with the recovery models.

I agree with what you say, but there are plenty of energy recovery models that are simple.
I chose a Spectra 150. This is available, as most of their models are, as a basic unit or a fully automatic one.
For the basic unit. the only electrical connection is to power the low pressure feed water pump. That's it.

Originally Posted by Oceansailor

My last advice. Buy as much capacity as you can afford from the beginning. Most people I have met say the same thing. "I should have bought a unit with more capacity"

This is good advice for the none energy recovery models. With these you need to make most of your water in the short time you running the engine or generator.

For an energy recovery model that will be running from solar it's much less important. The watermaker can run several hours a day everyday if needed. In fact frequent running is healthy for the watermaker.
They are quiet (at least the Specra is) and hums away in the background running from the solar panels.