US Water 200 GPD Watermaker - Techie advice/analysis

[MV Wanderlust]

We're shopping for our first boat. On our list of "nice to have" features is a reverse osmosis watermaker so we don't have to worry about the 70ish gallon limit on the tank. We found prices ranging from $4400 to well over $6000. Then I accidentally stumbled across this unit from US Water. It says it's RO, has three stages of filtering, and produces 200 gallons per day... for only $395??? Seems like I'm missing something here. We would appreciate it if someone who is more knowledgeable about these systems could take a look and shed some light.

Thanks.

John

[Jsta_Rebel]

It's probably for tap water in a home and not desalination of ocean water. Big difference. Good luck with finding your boat.

[Tellie]

These are home RO systems that take fresh water and use the RO process to filter the water further. These are operated on your homes water pressure usually around 35-60psi. A salt water RO system requires about 800psi, the equipment to create that pressure along with the equipment to handle that pressure and more.
If you happen to be in the Fort Lauderdale area this July 16th you can come to my one day (open to all CF members at no charge) watermaker class and learn all about RO watermakers for boats. Cheap breakfast, cheap lunch, but priceless information. This class is designed for current watermaker owners, those thinking about a watermaker in the future for their boat, and techs. Give me a shout if interested, the class is about full.


Halden Marine Services – Marine Watermakers, Solar Panels, Wind Generators
(954) 515-7077

[Lepke]

That 200 gpd is fresh water and probably won't deliver it's rating. Membranes are tested in relative warm water, I think about 77°F. And the 200gpd is 24 hour day.
It will work in a river or fw bay, but you'll need more filters and you'll need a uv light or some final sanitizing. I wouldn't want to drink the water of many rivers no matter how many filters.
I built my own, but probably spent more than buying one of the self installed, modular sets sold on Ebay and some people here. Still a few thousand $, but parts and filters are standard and available from many sources. I also got a lot of bad advice.
You really want one that runs a short time daily. I run mine about an hour a day when charging batteries.

[MV Wanderlust]

All really good advice and, after further review, you're all probably right. It's a home system designed for city water pressures, not desalinization. Thanks for taking a look.

[kelbylinn]

One other thing I learned after having our Spectra Water maker installed in our 42' Grand Banks, was that it really is rather useless if you are in coastal waters such as Mobile Bay area where Rivers flow into the water system. The pre-filters will fill up immediately simply because of the water residue. It does work well when we are off shore or much further south along the Florida coast but just a heads up.

[MV Wanderlust]

Interesting, kelbylinn. A good point. Our main concern is anchoring out for a week someplace remote like perhaps the Dry Tortuga's. With four people on board, we would go through 70 gallons of freshwater pretty fast.

[Tellie]

Originally Posted by kelbylinn

One other thing I learned after having our Spectra Water maker installed in our 42' Grand Banks, was that it really is rather useless if you are in coastal waters such as Mobile Bay area where Rivers flow into the water system. The pre-filters will fill up immediately simply because of the water residue. It does work well when we are off shore or much further south along the Florida coast but just a heads up.

This will be true for any boat based watermaker with standard pre-filtration. One of the reasons I always preach to my customers that these are off shore pieces of equipment or for areas where the water is nice and clean. But all major watermaker companies offer add on filtration systems designed for all types of environments like the heavier silted areas like you are probably experiencing. A back flushable media filter would most likely take care of this for you if you wanted to use your system in this area. We install a lot of land based systems where water conditions vary from clean water to almost mud so there are solutions. But my best advice for a typical cruiser is just to operate them in clean water.

www.HaldenMarineService.com

[Tellie]

Originally Posted by JohnEasley

Interesting, kelbylinn. A good point. Our main concern is anchoring out for a week someplace remote like perhaps the Dry Tortuga's. With four people on board, we would go through 70 gallons of freshwater pretty fast.

The Dry Tortuga's is a perfect place to operate a watermaker on the hook. 70 gallons for a week (7days) for 4 people. That's 2.5 gallons per day per person. There will be a watermaker in your future


Halden Marine Services – Marine Watermakers, Solar Panels, Wind Generators