Fresh Water in the Florida Keys

HeadedToTexas said:

Steady, B. I have no affiliation with any manufacturer and I am not pushing products; are you? I did a quick search on Amazon for a generic prefab RO unit as an example from that market segment of the RO industry. I am simply a guy who hopes to one day buy a boat. I am also a guy who likes to take a shower every night. And I'm a guy who has showered in enough campground showers to know I'd rather shower in my own than in a public one.

I have read here on many threads that among the benefits cruisers look forward to during marina stays are long hot showers. An expensive watermaker doesn't seem economically practical for coastal cruising (Florida being the subject here), but a system priced more in line with the application may be worth the effort, at least to me. Simple as that.

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Well, you started with "So I'm in the water business and the notion of expensive reverse osmosis systems was replaced by inexpensive systems a decade or more ago." That led to a connection. Then you kept pushing a product which by it's own information is not designed and will not work for "watermaker" use on a boat, especially in salt water. Yes a cheaper application is good, but not the one you linked. It's just really a cheap water purifier, to take city water and make it more pure. That's not what a watermaker does.

I agree and assumed Texas was in the business and wanted to enlighten us, at least it came across to me as such.

Sorry for the miscue, folks. My intentions were good, but my approach was sloppy. In addition to an aspiring trawler owner, I'm an employee-owner of a company that services boilers, cooling towers and other recirculating systems. We do not sell RO systems. I've got no horse in the race except the desire (someday) for a long, hot shower on board.

For what it's worth, a watermaker and the home unit I found on Amazon are both RO systems. "Cheap water purifiers" like the things they hang on refrigerator ice makers or thread onto your sink faucet are not the same at all.

Again, not selling either of them.

HeadedToTexas said:

Sorry for the miscue, folks. My intentions were good, but my approach was sloppy. In addition to an aspiring trawler owner, I'm an employee-owner of a company that services boilers, cooling towers and other recirculating systems. We do not sell RO systems. I've got no horse in the race except the desire (someday) for a long, hot shower on board.

For what it's worth, a watermaker and the home unit I found on Amazon are both RO systems. "Cheap water purifiers" like the things they hang on refrigerator ice makers or thread onto your sink faucet are not the same at all.

Again, not selling either of them.

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You still don't get it. That is a system designed for the home with city water. Read their own documents. I'm not the one saying it. They are. It does nothing for salinity. It meets none of the needs of a boater. I didn't say it was a "cheap water puririfier." It's not. It's not cheap. But it's designed to go under the sink or in the aquarium. No doubt your intentions were good. Wish your solution was actually viable for the purposes coastal boaters need. Unfortunately, it isn't. So back to the drawing board. Some of the home made units psneeld referred to. Or the lower priced watermakers.

Hmmm, I really think I do get it. I am keenly aware that the cheap unit from Amazon is a home unit designed for under sink installation. And it absolutely would impact salinity if you fed it salt water. Removing ions and larger molecules is what RO membranes do. Under the right conditions, of course.

My "solution" was merely a question and I should have made it far more clear that it was merely a question. It was answered in subsequent posts by several folks who replied about DIY and "assemble from parts" approaches. They made perfect sense. The point I tried to make was that this stuff keeps getting less expensive and it might make the financial question of whether or not to buy a watermaker when cruising Florida tip toward buying the watermaker if the components got cheap enough. See?

So this pdf file captures the components to diy one together. Definitely worth a read.

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0ahUKEwilzszQt83YAhUU-WMKHdk6C2cQFgg5MAI&url=https%3A%2F%2Fsublimesustenance.files.wordpress.com%2F2012%2F03%2Fhow-to-build-your-own-watermaker.pdf&usg=AOvVaw3koBGa2g99QetTIxyNokuA

HeadedToTexas said:

adding another belt driven water pump could provide the pressure. Making water while under way would mean time is on your side. Seems like a missed opportunity.

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There are many engine-driven units on the marine watermaker market. They are much more trouble-prone, so sell at a rate under 1% compared to electric ones.

CruiseRO sells both, so contact Rich and I'm sure he'll provide more specifics on why.

To me the most relevant factors, besides price, are:

Quality of initial and ongoing support

Reliability and ease of maintenance

Generic none-proprietary components, ease of repair in third-world conditions

AC vs DC powered

Amps per gallon, if energy efficiency is important in your setup (I suspect not so much here)

Gallons per hour, if time efficiency is more important.

One of the problems with engine driven belt RO units, is maintaining constant pressure. With the engine turning the the high pressure pump, as rpms change, so does the pressure. Sort of like our auxiliary disel generators. For optimal performance, you need constant engine speed.

I see more belt driven water makers running from a Kubota engine/generator than from the primary boats propulsion engine.

Here are some relevant notes and links to forum threads, sorry bout the formatting, just a dump from my KB tool


http://www.cruisersforum.com/forums/showthread.php?p=2547124


Spectra 150 gives you 6 gallons per

hour


cheap
https://www.rainmandesal.com


http://www.echotecwatermakers.com/dc_watermakers_yachts.htm


survivor35 is usually available on

eBay for about 200 to 300


http://www.trawlerforum.com/forums/showthread.php?t=7345


http://www.sailnet.com/forums/showthread.php?t=304362


CRUISE RO


http://www.trawlerforum.com/forums/showthread.php?p=615128


see Rich Boren email, also w/ fridge

stuff


http://www.cruisersforum.com/forums/showthread.php?t=193487


https://www.cruisingworld.com/desalination-decisions-watermakers


https://www.katadyn.com/en/ch/products/water-filters#/1/filter?categories=763


http://www.cruisersforum.com/forums/showthread.php?t=191083


http://www.cruisersforum.com/forums/showthread.php?t=188404

As I understand it (???) the pressure required to move water through the membrane depends on the salinity. So these household units may use the same membrane but will not work to desalinate unless there is a high pressure source or pump. No HP pump, no worky on a boat in sea water.

Membranes are pretty specific based on the water you’re trying to clean up. There is some cross over but you have to be careful or you can ruin the membrane. Our system is rated for ~20-24 gallons per hour in salt water @ 800 psi and greater than 10k ppm of TDS. If we are in brackish water we dial back the high pressure to maintain the ~20-24 gallons per hour of product water

A house hold type RO system runs at about 65 psi with 500 ppm tapwater TDS.

https://appliedmembranes.com/filmtec-dow-membranes.html

I can see the benefits of assembling a system from components. Confidence during maintenance if nothing else. The hand pumped Survivor35 is interesting, especially in cold weather. Like chopping wood, it heats you twice.

The van't Hoff Equation indicates that most seawater needs 406 psi just to break even, so creating and dealing with all that pressure accounts for a big chunk of the difference between under sink units and marine desal units. 800 psi is a lot.

what_barnacles said:

So this pdf file captures the components to diy one together. Definitely worth a read.

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Excellent article. I think I've seen the accompanying YouTube video. In addition to its DIY nature, I'm drawn to running the pump from the main engine. Food for thought. Thanks!

For a cruiser that wants to stay on the hook for extended times, the simplest might be a location where a dink can be used to carry FW from a city water tap.

Sure it might be a PIA if water consumption is high , but a sea water tap from a foot pump. or porting hot discharge water from a noisemaker (if in use) makes dish washing a snap.

We have used solar shower bags , for showering ,or hot dish washing .

Perhaps too much effort for some , but a snap once you do it a couple of times.

DLP said:

So anybody have an opinion on this add on craigslist for a watermaker

Brand new in box complete marine watermaker $1495.00 !! See video for details.

www.SeaWaterPro.com

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One thing that stood out to me from that video was the output of 30 GPH at little over 400 PSI. In my long experience with watermakers on board, I was never able to get that kind of output from seawater at those low pressures. Made me think that the source of water in that harbour was actually fresh water. I could be wrong. If it was a fresh water marina, then that was a misleading video.

Nightsky said:

One thing that stood out to me from that video was the output of 30 GPH at little over 400 PSI. In my long experience with watermakers on board, I was never able to get that kind of output from seawater at those low pressures. Made me think that the source of water in that harbour was actually fresh water. I could be wrong. If it was a fresh water marina, then that was a misleading video.

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Your right although it's not fresh, it would be brackish from my experience. You need 800 psi to get the results he quotes in full on salt water but at 400 psi, in brackish, I could see it.

Well I’m impressed. Larry must be our resident expert on Watermakers which is good to know I haven’t even tried to run mine. LMAO

It's the sort of kit that really should be run every few days or it won't work anymore, even fully pickled they don't like to just sit

Have any data on that?

Bigsfish said:

Well I’m impressed. Larry must be our resident expert on Watermakers which is good to know I haven’t even tried to run mine. LMAO

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Irv: What’s the one on the new boat? We can play with it in Ft P. I’m always up for an experiment.

I think transferring it to a dmaller vessel like mine might be the best experiment...just to make sure what its real range of usefulness is.

Plus Irv needs a rum still, not a water maker...

Guys thanks for helping me out. Scott you would have to remove your bunk to make room for my Dometic XTC 1800 Sea Exchange plus it has a Spot Zero 2000. Ive read the book but haven’t played with it but it worked during the survey. I’ll bring it with me and we can play after a dozen rums.

you did say a dozen...right?

I will have a few bottle to finish!

Bigsfish said:

But Scott, having a watermaker in the Bahamas out islands is fun when you wash down your boat and the blowboaters are looking.

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Upside to a timber boat - they hate fresh but love saltwater.

Simi

I never knew wood boat owners washed them in salt water, must be a new grade of S/S.

Bigsfish said:

Simi

I never knew wood boat owners washed them in salt water, must be a new grade of S/S.

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Number 8


https://www.woodenboat.com/ten-things-can-hurt-your-wooden-boat

Simi

After reading all that I am now more convinced than ever that God was correct inventing fiberglass. Wood boats are like teak, I love it in on your boat.