desalination

[roywilldo]

Considering a desal for a 4-8 person cat, mostly live aboard, any suggestions, manufactures, ideas I would be very grateful for any input please thank you stay safe and smiling Roy

[Sailmonkey]

Do you have a generator that you already run for battery charging or air conditioning?

If you regularly use a generator high output water makers make more sense.

[tkeithlu]

Independent of model/power source, I and think others like Sprectra units. Mine's a 160 GPD model, and it takes no end of neglect and abuse. I leave it for months at a time, and then just run it for 10 minutes to get the smell out. Eight years now and it's running fine with no maintenance.

Sizing? Think through a one-person budget without any Hollywood showers, mult by the size of your tribe, and don't plan to run it over 8 hours a day.

[CassidyNZ]

Depends where you live aboard. If you’re typically in marinas/harbours where source water quality is a problem, using a desalination unit (watermaker) would be tricky. If you’re habitually in clean water, it’s really a no-brainer.

The problem is you’re going to get a myriad of options off this board from home-made cheapies to very expensive automated systems. I hope you find a solution somewhere in the melee.

I went with my own home-made watermaker that produces 90 litres/hr and it cost me less than NZ$2500, using some used, discarded (but good) components and my own time. I originally never wanted one but now that I have it, I wouldn’t be without it.

[capn_billl]

I'll take a home made cheapie option.

[SVHarmonie]

If you are at all power limited, then the Spectra units make a lot of sense.

If you’ll be running a gen set to power it all the time, then a standard system has the advantage of simplicity. The reason that the home-brew systems are popular it that very few of the manufacturers avoid all kinds of fancy add ones that you don’t need. You need a feed filter, a high pressure pump, pressure vessel, membranes, controllable back-reassure valve, and a pressure gauge. Everything else is just nice. They are all available piecemeal for less than the cost of the commercial systems.

[CassidyNZ]

Originally Posted by tkeithlu

Sizing? Think through a one-person budget without any Hollywood showers, mult by the size of your tribe, and don't plan to run it over 8 hours a day.

Wow! 8 hours a day! Routinely I run mine for one hour every two days. But then there are normally only two, occasionally four people on board.

[Sailmonkey]

Originally Posted by CassidyNZ

Wow! 8 hours a day! Routinely I run mine for one hour every two days. But then there are normally only two, occasionally four people on board.

We’re two people and run our 35l/hr unit 1-2 hours a day.

Unless we’re motoring and the urge to spray everything with fresh water takes over.

[kmacdonald]

Homemade gas powered 40 gph unit. Honda GX120 engine. Takes less fuel than the outboard. Put a quart of fuel in it and run it till it's empty. Saves weight carrying a lot of water. Plenty of how tos on the internet but it's about $2500 to $3000 depending how complex you think you need and the quality of components. You could do it a lot cheaper but it wouldn't last.

[Olorin]

We run a 12 volt based boat so we went for a Spectra Cape Horn water-maker.

It makes 60 liters (16 gal) per hour using 18 amps. With the two of us on board we use about 60 liters per day so every five days we run it for five hours, typically when the batteries are full. We have 1250 watts of solar so the water is made using energy we would not be harvesting otherwise.

A good friend did not have the option of sufficient solar panels so he went with the option of running his engine for 1 hour a day. His home built engine driven system made 60 gallons/hour. So he and his family of four had hot showers every night before bed.

There are many ways to skin this cat.

Good luck.

[Cheechako]

For simple I'd go with the Spectra. You can put a motor driven watermaker on one of your engines, I did in my cat. But it's not as simple and easy and requires monitoring etc.
I used my water maker everywhere, in harbor or not.

[CassidyNZ]

Originally Posted by Sailmonkey

We’re two people and run our 35l/hr unit 1-2 hours a day.

Unless we’re motoring and the urge to spray everything with fresh water takes over.

Yes, look, when we’re motoring anyway, we make water. We have 1000l tankage so if we’re going to run the engine anyway, the watermaker fills the tanks.

For clarity, ours is not engine driven - we have a 110v motor which uses 120A to run so we run a big-frame alternator on the engine to prevent the watermaker draining the batteries.