Kevins new watermaker

ksanders · Jan 26, 2016

Pete

Great comments!

Instead of quoting your post I'll offer some comments..

I had the same question regarding the Murdock fittings. When I googled the Murdock fittings I found that they are in wide use among RO manufacturers, so I had no problem using them. I found them easy to use and only had one leak which was my fault.

Regarding their use below the waterline, well the installation does not require that.

The salt water inlet to the system is the filter assembly. That has a 1/2" FPT fitting. You can run whatever you want to it from your seacock. In my installation I used a Raritan sea strainer which is mounted right at the waterline as it should be.

Good installation practice would dictate that the filters also be above the waterline alleviating any below the waterline concerns. The concept here is that we want to minimize the below the waterline connections and devices.

The boost pump I have no problem with. Yes they could have used a different pump. They chose that pump though. I will not pretend to be a watermaker engineer and I am not going to question every design decision they made. I bought a unit with a nice manufacturers warranty, and assume that it is engineered for its intended purpose.

Best of luck on finishing your install. I found mine to be easy and straightforward.

Alaskan Sea-Duction · Jan 26, 2016

Awesome install Kevin! I now have this on my bucket list right after auto pilot...

MYTraveler · Mar 2, 2016

My question is for Kevin and Pete and anyone else with experience with Cruise RO Watermakers:

Background -- I have two 600 gpd watermakers on board. They worked fine for several years but (the high pressure pumps) have now failed and the manufacturer can't supply parts or replacement pumps. So, I am in search of two new water makers from a different manufacturer. Along the way, I have learned that my current brand uses proprietary osmotic filters, so the cost of replacement is about $1,000 (each) more than it would otherwise be.

What I liked about my current watermakers is that everything was automated. I press one button and it begins production, with a green light to tell me it is making good water. When I am done I press a single button to stop it and the green light goes away. The freshwater flush happens automatically, even if I don't leave my freshwater pump turned on (which I don't like to do when I will be away from the boat).

Now my question -- how much attention is necessary to keep the watermaker producing at near its rated capacity. A prior water maker I had required the adjustment of pressure valves. Too little pressure and little or now production. Too much pressure and the thing would shut itself off. If it were only a matter of setting and forgetting, that would be fine, but with my prior unit, pressure would gradually build until it hit the shut off point. So, in practice, I would have to adjust the water maker several times during its first hour of production and I would have to check on it every hour or so after.
My question is, with the Cruise RO unit, how much adjustment, during production, is necessary?

Alaskan Sea-Duction · Mar 2, 2016

MYTraveler said:
My question is for Kevin and Pete and anyone else with experience with Cruise RO Watermakers:

Background -- I have two 600 gpd watermakers on board. They worked fine for several years but (the high pressure pumps) have now failed and the manufacturer can't supply parts or replacement pumps. So, I am in search of two new water makers from a different manufacturer. Along the way, I have learned that my current brand uses proprietary osmotic filters, so the cost of replacement is about $1,000 (each) more than it would otherwise be.

What I liked about my current watermakers is that everything was automated. I press one button and it begins production, with a green light to tell me it is making good water. When I am done I press a single button to stop it and the green light goes away. The freshwater flush happens automatically, even if I don't leave my freshwater pump turned on (which I don't like to do when I will be away from the boat).

Now my question -- how much attention is necessary to keep the watermaker producing at near its rated capacity. A prior water maker I had required the adjustment of pressure valves. Too little pressure and little or now production. Too much pressure and the thing would shut itself off. If it were only a matter of setting and forgetting, that would be fine, but with my prior unit, pressure would gradually build until it hit the shut off point. So, in practice, I would have to adjust the water maker several times during its first hour of production and I would have to check on it every hour or so after.
My question is, with the Cruise RO unit, how much adjustment, during production, is necessary?

Good question.....

sunchaser · Mar 2, 2016

Alaskan Sea-Duction said:
Good question.....

Well if you believe the ads and sales guys, no worries.

I have intentionally not installed an RO unit because (God Bless Art) has about 2 to 3 weeks capacity and 400 gallons. The RO unit in our house is serviced once per year and can produce about 20 to 40 gallons per day full beat. On a boat that is all we'd need, but then the power supply issue comes into it.

I've been on vessels with true 400 to 2,000 gallon per day units. Lots of work to keep them performing properly. Onerous, no. Expensive, yes. Village Marine is my choice.

jungpeter · Mar 2, 2016

To MYTraveler:

Sorry, can't yet comment on your direct question regarding the amount of adjustment required to the Cruise RO watermaker hi-pressure pump after it's in operation. I just finished my install, and haven't had a chance to adequately test it yet. But I have no reason to believe that it will require any attention during operation, other than to monitor water tank capacity, and to shut down the watermaker when the tank's full.

i CAN comment on your more general inquiry, regarding your desire for a "start and forget" watermaker. Cruise RO aint' it. With the exception of the optional automatic fresh water flush, all operation of the Cruise RO unit is manual. Hence it's popularity with those of us so inclined to be "hands-on" owner/operators.

And, with regard to your prior watermaker that apparently required significant adjustment of it's operating pressure during operation, I can only surmise that the unit may have had either significant RO membrane fouling, or perhaps fouling in the pre-filters upstream of the high pressure pump. My experience with a 1985-vintage Sea Recovery 400 GPD watermaker, which was also a manual unit, required NO adjustment of the hi-pressure outlet pressure to maintain water production, hour after hour after hour of use for many years. Regular maintenance of filters, and occasional replacement of membranes required, of course.

Another general comment, if I may be so bold. Watermakers love to be used. They seem to require less maintenance the more hours they accumulate at any one time. Relying on much of the prevalent watermaker manufacturers' hype regarding "automatic operation, low maintenance" is a ticket to disappointment. Run 'em often, fresh water flush periodically, pickle them properly if they must sit for months at a time, and pay close attention to the pre-filter condition. Works good, lasts long time.

Regards,

Pete

ksanders · Mar 2, 2016

MYTraveler said:
My question is for Kevin and Pete and anyone else with experience with Cruise RO Watermakers:

Background -- I have two 600 gpd watermakers on board. They worked fine for several years but (the high pressure pumps) have now failed and the manufacturer can't supply parts or replacement pumps. So, I am in search of two new water makers from a different manufacturer. Along the way, I have learned that my current brand uses proprietary osmotic filters, so the cost of replacement is about $1,000 (each) more than it would otherwise be.

What I liked about my current watermakers is that everything was automated. I press one button and it begins production, with a green light to tell me it is making good water. When I am done I press a single button to stop it and the green light goes away. The freshwater flush happens automatically, even if I don't leave my freshwater pump turned on (which I don't like to do when I will be away from the boat).

Now my question -- how much attention is necessary to keep the watermaker producing at near its rated capacity. A prior water maker I had required the adjustment of pressure valves. Too little pressure and little or now production. Too much pressure and the thing would shut itself off. If it were only a matter of setting and forgetting, that would be fine, but with my prior unit, pressure would gradually build until it hit the shut off point. So, in practice, I would have to adjust the water maker several times during its first hour of production and I would have to check on it every hour or so after.
My question is, with the Cruise RO unit, how much adjustment, during production, is necessary?

When you start up the water maker you adjust the pressure on the membrane, and you adjust the boost pump to keep sufficient flow into the high pressure pump.

When in operation I have not had to fiddle with it, although the first few times it did watch it very closely.

Shutting it down is a matter of reducing the membrane pressure, then shutting down the pumps.

One reason I bought the Cruise RO unit is that it does not use any proprietary parts. I ran D&B credit reports on a couple of water maker companies and they tend to be very small companies that appear to amount to a job for the owners and not much more. Cruise RO is no exception, the difference is that customers are not dependent on them for maintenance parts or consumables.

I actually searched for the main components like the high pressure pump, membranes, and housings and found the exact same brands readily available.

MYTraveler · Mar 2, 2016

jungpeter said:
To MYTraveler:

Sorry, can't yet comment on your direct question regarding the amount of adjustment required to the Cruise RO watermaker hi-pressure pump after it's in operation. I just finished my install, and haven't had a chance to adequately test it yet. But I have no reason to believe that it will require any attention during operation, other than to monitor water tank capacity, and to shut down the watermaker when the tank's full.

i CAN comment on your more general inquiry, regarding your desire for a "start and forget" watermaker. Cruise RO aint' it. With the exception of the optional automatic fresh water flush, all operation of the Cruise RO unit is manual. Hence it's popularity with those of us so inclined to be "hands-on" owner/operators.

And, with regard to your prior watermaker that apparently required significant adjustment of it's operating pressure during operation, I can only surmise that the unit may have had either significant RO membrane fouling, or perhaps fouling in the pre-filters upstream of the high pressure pump. My experience with a 1985-vintage Sea Recovery 400 GPD watermaker, which was also a manual unit, required NO adjustment of the hi-pressure outlet pressure to maintain water production, hour after hour after hour of use for many years. Regular maintenance of filters, and occasional replacement of membranes required, of course.

Another general comment, if I may be so bold. Watermakers love to be used. They seem to require less maintenance the more hours they accumulate at any one time. Relying on much of the prevalent watermaker manufacturers' hype regarding "automatic operation, low maintenance" is a ticket to disappointment. Run 'em often, fresh water flush periodically, pickle them properly if they must sit for months at a time, and pay close attention to the pre-filter condition. Works good, lasts long time.

Regards,

Pete

Pete,
Thanks for your reply and please let me know how it goes after you test your unit. It would be nice to know whether the thing can run without continued adjustment. (My understanding is that my current unit monitored and adjusted pressure, automatically.)

As for frequency of use, I totally agree. Most of the use of my boat is for multi-day stretches and the watermakers get several hours use per day.

As for maintenance, is there anything to do besides change pre-filters? On my current unit there is not, and I am convinced no amount of additional maintenance would have prevented the failures.

Lastly, you mentioned that you need only remember to shut the unit off when the tank is full. As I recall, my unit specified that the feed line have zero (or very limited) backpressure. Because I was concerned that overfilling the tank (and thereby adding the pressure to left the water to the level of the vent) might cause problems, I had a separate overflow line put in. As a result, I never had to worry about shutting off the watermakers.

Thanks,
Rick

sunchaser · Mar 2, 2016

Kevin

Good work and thanks for sharing. A few questions:

--Is the Seward Harbor clean enough so unit can be run there?
--Does the higher suspended solids in AK glacial waters present a problem
--Have you pickled unit yet, if so how long does it take you?
--Where do you buy pre-filters and RO membranes?
--What is power draw?

Thanks

MYTraveler · Mar 2, 2016

ksanders said:
When you start up the water maker you adjust the pressure on the membrane, and you adjust the boost pump to keep sufficient flow into the high pressure pump.

When in operation I have not had to fiddle with it, although the first few times it did watch it very closely.

Thank you for the follow-up! Good information. -Rick

ksanders · Mar 2, 2016

sunchaser said:
Kevin

Good work and thanks for sharing. A few questions:

--Is the Seward Harbor clean enough so unit can be run there?
--Does the higher suspended solids in AK glacial waters present a problem
--Have you pickled unit yet, if so how long does it take you?
--Where do you buy pre-filters and RO membranes?
--What is power draw?

Thanks

Seward harbor is just fine. We have a 10' average tide change so nothing stays here long.

I have not seen a problem with solids, but I don't know how long pre-filters last in other locations so I don't have a comparison.

In normal use you do not need to pickle the unit. I have the auto rinse option installed. Every 5 days it runs the boost pump for 10 minutes which pushes fresh water across the membrane face and insures there is no time for the growth of anaerobic bacteria. The auto wash uses tank water run through a charcoal filter so you don't have to leave a seacock open.

I did pickle the unit and then winterized it las fall. It takes all of 10 minutes to pickle the unit.

I can buy the pre filters at Home Depot. Have not had to replace the membranes but they are standard Dow units and they are available online from a variety of sources for about $200 each.

The power draw is 13 amps AC. At that power draw we make 40 gallons per hour. A couple of hours a day and we're good. We use allot of water with the clothes washer, etc... We also eliminated the salt water wash down, and re-rerouted potable water to the two hose bibs. This makes washing the boat easy!

I never take on dock water anymore. No need. It has chlorine and fluoride, and goodness knows what chemicals in it. RO water is just pure H2O.

kulas44 · Mar 2, 2016

I have an older Sea Recovery unit that was in my trawler for awhile. I say it was a Sea Recovery because some of the parts had that name on them. Almost everything was generic or could be retro fitted. The supply pump was a standard 1/3 hp 120 volt 1750 rpm centrifugal with a pressure bypass befor the prefilter. The high pressure pump was a CAT (IIRC) with a 220 volt 3/4 hp motor. Pressure on the high side of the membranes was controlled by an adjustable regulator. Product water had a sensor that told you if it was suitable to go to the tank,with a green light. A flow sensor gave you the GPH. High and low side gauges.3 Generic membranes that are available everywhere and can be had in whatever size needed. I think my unit was rated 400 GPD. Nothing complicated about it and it always worked. I still cant figure why these things are so expensive and cause sailboaters so much grief. The average mechanically inclined boat owner could put together a reliable system for about $1500, I think. With new components.

jungpeter · Mar 2, 2016

Hi Rick (MYTraveler),

Every watermaker manufacturer has suggested maintenance for their units. With regards to my previously-owned Sea Recovery 400 GPD unit, the maintenance I followed was right out of their owner's manual. I doubt there's anything other than manufacturer's-prescribed maintenance that can prolong the life of, or improve the performance of watermakers.

Not sure about the need to minimize pressure head on the product water. The product water is ideally delivered out of the membrane at atmospheric (zero head) pressure. Any head loss to be overcome from there to the water tank, and hence overboard via the vent hose when full will reduce product volume somewhat. However, given that the pressure on the raw water side of the membrane is at something like 900 psi, little volume will be lost if the product side of the membrane sees something like 10 psi head caused by filling your tank either from the bottom, or overfilling and venting some feet higher overboard. Maybe if you have giant tanks, and vent WAY above the waterline, but I'm still not sure about this point. But, as your rotometer that measures flow rate through the system is downstream from the membranes, it will let you know if flow rate doesn't match factory-promised numbers.

Perhaps a design professional from the watermaker industry will chime in here, and shed some light on this particular topic. I may be all wet (!), but my product water is delivered from the membrane to the bottom of my water tank, and when the tank's full, I observe it venting overboard, and shut off my watermaker. Easy-peasy, no harm to date.

Regards,

Pete

ksanders · Mar 2, 2016

jungpeter said:
Not sure about the need to minimize pressure head on the product water. The product water is ideally delivered out of the membrane at atmospheric (zero head) pressure. Any head loss to be overcome from there to the water tank, and hence overboard via the vent hose when full will reduce product volume somewhat. However, given that the pressure on the raw water side of the mem. I may be all wet (!), but my product water is delivered from the membrane to the bottom of my water tank, and when the tank's full, I observe it venting overboard, and shut off my watermaker. Easy-peasy, no harm to date.

Pete

That's the way I do it as well Pete. I teed the product water into the suction side inlet to my potable water pump.

People do not understand head pressure very well. They think that the whole water tanks pressure is creating head pressure on the water maker. Then at the same time they recommend that you tee the product water into the tank fill hose.

The reality is that the head pressure on the water maker is defined only by the height of the water Column that must be lifted. By that definition there is more head pressure on the pump if you connect it to the fill which is above the tank. If you connect the product water output to the bottom of the tank the head pressure is the rise to the bottom of the tank, plus the depth of the water in that tank. The tank could be a zillion gallons or one ounce, and the pressure would be the same if the depth is the same.

MYTraveler · Mar 2, 2016

ksanders said:
The reality is that the head pressure on the water maker is defined only by the height of the water Column that must be lifted. By that definition there is more head pressure on the pump if you connect it to the fill which is above the tank. If you connect the product water output to the bottom of the tank the head pressure is the rise to the bottom of the tank, plus the depth of the water in that tank. The tank could be a zillion gallons or one ounce, and the pressure would be the same if the depth is the same.

I think I understand the concept, but please correct me if I am missing something. My manufacturer recommended that the output would, ideally, be above the top of the tank, with a downhill run from the output into the tank (or another line feeding the tank). In that circumstance, I believe that the pressure on the feed line is the same whether the connection is made at the bottom of the tank or the top of the tank, since it is below the watermaker output. But, my mfg's instructions went on to limit the permissible pressure if either a) the unit output were below the top of the tank (in which case the head pressure would equal the height of the water column between the unit output and the top of the tank (at least when it is full), regardless where between the top of the tank and the bottom of the tank the input connection is made, or b) the overflow vent is above the top of the tank (in which event the head pressure would (if the tank were overflowing) be increased by the height of the water column between the elevations of the top of the tank and the level of the vent (or the highest point of its connecting line, if higher, as would be the case in some installations). My problem was that the vent height was enough higher that it created in impermissible pressure potential, necessitating my installation of a lower vent point.

Thanks for the help guys (and if I am misunderstanding something, please explain).

ksanders · Mar 2, 2016

MYTraveler said:
I think I understand the concept, but please correct me. My manufacturer recommended that the output would, ideally, be above the top of the tank, with a downhill run from the output into the tank (or another line feeding the tank). In that circumstance, I believe that the pressure on the feed line is the same whether the connection is made at the bottom of the tank or the top of the tank, since it is below the watermaker output. But, my mfg's instructions went on to limit the permissible pressure if either a) the unit output were below the top of the tank (in which case the head pressure would equal the height of the water column between the unit output and the top of the tank (at least when it is full), regardless where between the top of the tank and the bottom of the tank the input connection is made, or b) the overflow vent is above the top of the tank (in which event the head pressure would (if the tank were overflowing) be increased by the height of the water column between the elevations of the top of the tank and the level of the vent (or the highest point of its connecting line, if higher, as would be the case in some installations). My problem was that the vent height was enough higher that it created in impermissible pressure potential, necessitating my installation of a lower vent point.

Thanks for the help guys (and if I am misunderstanding something, please explain).

You are correct.

If you install the membranes above the tank, and above the tee in point then there is zero head pressure.

Actually there would be a negative head pressure caused by the weight of the water column (siphon effect).

In a practical sense my membranes are about about 4' below my vent and the system works just fine. I run the water maker until the vent overflows fairly frequently.

kulas44 · Mar 2, 2016

Wait a minute, we have 900 psi on one side and the weight of water on the other. Just how many angels can sit on a pinhead. Its a non issue, almost immeasurable.

Rebel112r · Mar 9, 2016

I finally got all my bits and pieces together and put my watermaker to use this last week. All parts were picked up at marine surplus or marina yard sales. Only new purchases were pressure vessel, membrane, and filters. Also misc connectors and fittings. Had available thru hulls, so no new boat holes. Watermaker testing shows flow rate of 2.75gpm, pressured to 800 pounds and producing 25 gph at a water quality of around 50 ppm. Total cost of watermaker was about $1200

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Rebel112r · Mar 9, 2016

Took the easy way out to feed water to tanks, drill and tap to existing fittings. This project was to go in previous boat, never got done, finally done now. Will only use during longer trips, as boat has 350 gal storage. Will remove membrane and pickle in a storage tube, rather than run chemicals thru whole system. The membrane and filters came from Cruise RO, Great to do business with.

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kulas44 · Mar 10, 2016

Excellent. Nice to see that you didnt have to spend big $$$.

Capt.Bill11 · Mar 10, 2016

MYTraveler said:
Background -- I have two 600 gpd watermakers on board. They worked fine for several years but (the high pressure pumps) have now failed and the manufacturer can't supply parts or replacement pumps. So, I am in search of two new water makers from a different manufacturer. Along the way, I have learned that my current brand uses proprietary osmotic filters, so the cost of replacement is about $1,000 (each) more than it would otherwise be.

I can almost guarantee the water maker manufacturer did not build there own pumps. Most water maker high pressure pumps are pressure washer pumps. Find the specs on your pumps and just get replacements.

What I liked about my current watermakers is that everything was automated. I press one button and it begins production, with a green light to tell me it is making good water. When I am done I press a single button to stop it and the green light goes away. The freshwater flush happens automatically, even if I don't leave my freshwater pump turned on (which I don't like to do when I will be away from the boat).

I would think you had to at least leave the breaker on for the unit to automatically back flush. If your electronics are still good and/or you can still get parts for them, just buy new pumps and somebody else's membranes that match you units old membrane specs.

Now my question -- how much attention is necessary to keep the watermaker producing at near its rated capacity. A prior water maker I had required the adjustment of pressure valves. Too little pressure and little or now production. Too much pressure and the thing would shut itself off. If it were only a matter of setting and forgetting, that would be fine, but with my prior unit, pressure would gradually build until it hit the shut off point.

That should not be happening. The pressure should stabilize and you shouldn't have to adjust it after it does.

MYTraveler · Mar 10, 2016

Capt.Bill11 said:
I can almost guarantee the water maker manufacturer did not build there own pumps. Most water maker high pressure pumps are pressure washer pumps. Find the specs on your pumps and just get replacements.

I was told by a former senior executive of my manufacturer who is now working in a related field but not for a direct competitor (so no incentive to steer me toward his new direction) that the (high pressure) pumps were manufactured for the US military (I don't remember the application, but I don't think it was water makers) but that the US military no longer requires these pumps so they are no longer manufactured by anyone.

As it is, I intend to investigate the cost of either replacement of both units with ones like Kevin's that are 100% generic parts, or the salvage of as much of my system as can be made operable with generic replacements for everything else. I am skeptical that I will be able to use the "brains" of my current systems in that context, however.

Capt.Bill11 · Mar 10, 2016

MYTraveler said:
I was told by a former senior executive of my manufacturer who is now working in a related field but not for a direct competitor (so no incentive to steer me toward his new direction) that the (high pressure) pumps were manufactured for the US military (I don't remember the application, but I don't think it was water makers) but that the US military no longer requires these pumps so they are no longer manufactured by anyone.

As it is, I intend to investigate the cost of either replacement of both units with ones like Kevin's that are 100% generic parts, or the salvage of as much of my system as can be made operable with generic replacements for everything else. I am skeptical that I will be able to use the "brains" of my current systems in that context, however.

The brains just control relays and valves in most cases. As long as the voltages, amperages, pressures, etc. are the same, or with in tolerances down stream, I would think the brains would be happy.

MYTraveler · Mar 10, 2016

Capt.Bill11 said:
The brains just control relays and valves in most cases. As long as the voltages, amperages, pressures, etc. are the same, or with in tolerances down stream, I would think the brains would be happy.

I am concerned about the interface with the high pressure pump, which I admittedly have not studied. If the sensors are on that pump, I will have the problem of getting comparable sensors for the replacement pump. Similarly, if the pressure valves are integral to the pump, I will have the difficulty of finding comparable valves to control the replacement pump.
I do intend to figure out exactly how that pump works and whether any replacements is available. Thanks for your suggestions. -Rick

Capt.Bill11 · Mar 10, 2016

MYTraveler said:
I am concerned about the interface with the high pressure pump, which I admittedly have not studied. If the sensors are on that pump, I will have the problem of getting comparable sensors for the replacement pump. Similarly, if the pressure valves are integral to the pump, I will have the difficulty of finding comparable valves to control the replacement pump.
I do intend to figure out exactly how that pump works and whether any replacements is available. Thanks for your suggestions. -Rick

In all cases that I can recall there are no sensors mounted directly on the pumps. But yours could be the exception.

Simi 60 · Mar 11, 2021

Commenting to find and read later

TBill36 · Mar 11, 2021

A word of caution if you install the way I did. Hopefully I can explain this clearly.

I have stand alone through hull for the water system. There is a ball valve to shut it off when not in use. I also have a solenoid controlled valve with a timer plumbed into the fresh water to rinse the water maker membranes every few days. So when I'm not making water the through hull is shut and the fresh water gets circulated to keep bacteria from growing - per normal operation practices. I did not have a shut off valve at the solenoid controlled valve.

The problem occurred when not making water with the through hull open. When under way, there was enough pressure from the water maker intake to push open the solenoid valve and let salt water into the fresh water. It was a simple fix to add a manual shut off valve at the solenoid valve, so whenever I'm cruising or making water, nothing can backflow through the solenoid valve.

Kevins new watermaker

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