How to maintain a dormant water maker?

[softdown]

Originally Posted by Flyingriki

Just curious. That guy in the video says his system stays just fine if rinsed in clean water. Is that not true?

He does say that it worked for him. Keep in mind that he built an extra-ordinarily good watermaker and performs ideal maintenance by flushing it with freshwater after every use.

While they do measure pH and TDS regularly, they have no way to measure bacteria. They got away with long term storage with no precautionary measures since nobody got sick.

People think that low TDS measurements guarantee quality water. Low TDS measurements indicate that your watermaker is doing what it is built to do. That is remove TDS....total dissolved solids.

Do watermakers effectively remove bacteria? Especially after long term storage? Opinions will likely vary. I do not know.

[Kenomac]

Originally Posted by softdown

He does say that it worked for him. Keep in mind that he built an extra-ordinarily good watermaker and performs ideal maintenance by flushing it with freshwater after every use.

While they do measure pH and TDS regularly, they have no way to measure bacteria. They got away with long term storage with no precautionary measures since nobody got sick.

People think that low TDS measurements guarantee quality water. Low TDS measurements indicate that your watermaker is doing what it is built to do. That is remove TDS....total dissolved solids.

Do watermakers effectively remove bacteria? Especially after long term storage? Opinions will likely vary. I do not know.

For someone who claims to be such an expert on the watermaker subject, you sure write some foolish comments.

Of course a properly working watermaker removes all bacteria, bacteria are certainly MUCH LARGER than a sodium ion. The comment above almost tops your chorine rinse recommendation.

You might wanna quit while you're behind.

[Julian Alcorso]

I agree with the posts saying your membranes are probably stuffed.
I am a retired winemaker and have been using reverse osmosis membranes for the last 25 years.
My experience has taught me the following:
1. Preparation for long term storage:
i) Rinse with fresh filtered water for 5 minutes (water to wast)
ii) Circulate a 1% solution of caustic soda (1 gm/litre) for 5 minutes at least
iii) Rinse with fresh filtered water for 2 minutes (water to wast)
iv) Circulate a 2% solution of citric acid (2 gm/litre) for 5 minutes at least
v) Circulate with a solution of 5% Sodium Metabisulphate (SMS). PMS is OK here.
vi) Stop the pump with the housings full and close off all inlet and outlet valves.

The SMS or PMS can be sourced from any home brew shop. DON'T use Camden tablets. You must be careful with these powders as they will cause breathing difficulties if inhaled. I use a respirator when mixing and circulating.

2. Thorough cleaning and/or regeneration:
i) Rinse with fresh filtered water for 5 minutes (water to wast)
ii) Circulate a 1% solution of caustic soda (1 gm/litre) for 5 minutes at least
iii) Rinse with fresh filtered water for 2 minutes (water to wast)
iv) Circulate a 2% solution of citric acid (2 gm/litre) for 5 minutes at least
v) Rinse with fresh filtered water for 5 minutes (water to wast)
This method thoroughly cleans the membranes and then stores them in a slightly acid sterile environment.

I have used this method on massively expensive large membranes and it is totally effective. Of course I use them on my boat membranes as well.

Tips: The caustic is more efficacious at 40 - 50 degrees Centigrade.
Only use clean filtered and chlorine free water
Care when handling Caustic
Citric acid can be substituted with tartaric acid or even sulphuric acid CARE !!!!!
The circulation times can be extended for better results
The rinse times are the absolute minimum and can be increased.

Good luck!!!

[RickyEM]

Thank you for this detailed procedure. What is meant by "wast" ? Do you mean waste?

Originally Posted by Julian Alcorso

I agree with the posts saying your membranes are probably stuffed.
I am a retired winemaker and have been using reverse osmosis membranes for the last 25 years.
My experience has taught me the following:
1. Preparation for long term storage:
i) Rinse with fresh filtered water for 5 minutes (water to wast)
ii) Circulate a 1% solution of caustic soda (1 gm/litre) for 5 minutes at least
iii) Rinse with fresh filtered water for 2 minutes (water to wast)
iv) Circulate a 2% solution of citric acid (2 gm/litre) for 5 minutes at least
v) Circulate with a solution of 5% Sodium Metabisulphate (SMS). PMS is OK here.
vi) Stop the pump with the housings full and close off all inlet and outlet valves.

The SMS or PMS can be sourced from any home brew shop. DON'T use Camden tablets. You must be careful with these powders as they will cause breathing difficulties if inhaled. I use a respirator when mixing and circulating.

2. Thorough cleaning and/or regeneration:
i) Rinse with fresh filtered water for 5 minutes (water to wast)
ii) Circulate a 1% solution of caustic soda (1 gm/litre) for 5 minutes at least
iii) Rinse with fresh filtered water for 2 minutes (water to wast)
iv) Circulate a 2% solution of citric acid (2 gm/litre) for 5 minutes at least
v) Rinse with fresh filtered water for 5 minutes (water to wast)
This method thoroughly cleans the membranes and then stores them in a slightly acid sterile environment.

I have used this method on massively expensive large membranes and it is totally effective. Of course I use them on my boat membranes as well.

Tips: The caustic is more efficacious at 40 - 50 degrees Centigrade.
Only use clean filtered and chlorine free water
Care when handling Caustic
Citric acid can be substituted with tartaric acid or even sulphuric acid CARE !!!!!
The circulation times can be extended for better results
The rinse times are the absolute minimum and can be increased.

Good luck!!!

[softdown]

Spent a few minutes checking into the ability of desalinators to remove bacteria. The manufacturers, at least, think they do. For example:
From; Desalination FAQ Does desalinator remove harmful bacteria from sea water ?

A. Definitely. Reverse osmosis membranes are capable of removing 99.9+ % of bacteria. This level of removal is sufficient for most sea waters which contain some bacteria and other micro-organisms. The feed water intake pipe should not be located close to some source of contamination like sewer discharge point. Otherwise the reverse osmosis membranes will be overloaded with bacteria.

[SV THIRD DAY]

Originally Posted by Tellie

opc orn: I'll let Rich, he loves this kind of stuff.opcorn :

Ha ha ha....well I was trying to turn over a new leaf, but come on....Chlorine... Then after giving such horrible bogus advice he doubles down to become the site's new authority on RO Membranes? Excuse me as I sell a new replacement membrane to some poor soul that took this fellas first advice!

It seems as if once a month we have a new keyboard internet chat room "expert" drops in and gives bogus advice and yet another round of internet rumors and dock rumors are born.

What next...Urine is Sterile and a good preservative for membranes?
(Been There - Done That and sold the poor guy replacement membranes)

The Best Preservative for long term storage is Propylene Glycol in a 40-50% concentration...hands down.
Next best is the pickling reagent recommended by your water maker manufacturer. I would say 1yr is tops before flushing it out and re-pickling, but that's because I have a Warranty Membrane to lose if it goes bad as a manufacture, so of course I'm going to err on the side of caution rather than an upset cruiser with a dead membrane in Tahiti. Can it go longer...sure maybe, but you're on your own with that risk.

Now why do some folks tell stories of a membrane being pickled for two years being DEAD and another guy tell a story of a 6yr pickled membrane being as good as new? Easy....one pickling job was done well and was able to kill all of the bacteria in the system while the other pickling job wasn't. It's really that simple.

We all know there are different amounts of "animals" living in different bodies of water and some are more resistant to the pickling solution than others. The worst thing you can do it leave your dirty-nasty-smelly prefilters in place, pickle and then leave for a year. All it takes is for a few nasty bacteria to survive somewhere in the prefilters elements that didn't get a good flush of preservative and then as soon as the preservative loses it's punch...boom...there is a Biology Field Party Kegger with lots of copulation going on inside your water maker. It's why you get different anecdotal stories that people then mistakenly try to apply universally. Spin the wheel of water maker inadequate maintenance long enough and you will be bound to land on the New Membrane prize.

Why do you need to pickle in the first place?

It's all about bacteria...some Cruising Bozo Hobo made an Educational YouTube video about it....Take a look.

https://www.youtube.com/watch?v=WjyA0BOharw

[senormechanico]

Originally Posted by JDeachman

Senormechanico: What is "product water"? Is this different from pickling.

I just switch the raw water input (salt water I'm floating in) to the fresh water I just produced (fresh water tank).
After the salt is run out, the DC current drops, the pressure gauge drops and stablizes along with the product GPM. When stabilization of those three things happens ( a minute or two) I know it's full of fresh water.

For extended non use, I remove the 5 micron filter.
The membrane sits in its own product water for six months with no ill effects in the Pacific North West.
I have had this in the boat since 2000 with never ever using any pickling solutions.

BTW, We're leaving for two months on the boat in one week. Desolation Sound here we come again.
Back here around Sept first.
Long distance internet is pretty sketchy up there, but I'll try to drop in when possible.
If you're up there and see Flexible Flyer, stop by and say hi !

[SV THIRD DAY]

Originally Posted by senormechanico

I just switch the raw water input (salt water I'm floating in) to the fresh water I just produced (fresh water tank).
After the salt is run out, the DC current drops, the pressure gauge drops and stablizes along with the product GPM. When stabilization of those three things happens ( a minute or two) I know it's full of fresh water.

DANGER....DANGER.....DANGER......

The danger of following advice on the internet vs the instructions your water maker company spent the time writing up in the manual can cost you your membrane.

If you switch from sea water to fresh water with a water maker that uses a back pressure regulating valve and try trick above....pop.....you could blow your RO Membrane.

Know your water maker and be careful before trying the "I heard it on the internet" tricks because some of the results could be costly.

Ok ok...ok....you can't play the DANGER CARD and not explain a bit more. So WHY is this the case?
Because a membrane is rated for a maximum flux (or water passing through the membrane) so if your system is operating at 800psi and happily making 20GPH on sea water if all of a sudden the sea water is gone and the unit is running only on fresh water there is now much less osmotic pressure and the 800psi will force way too much water through the membrane than the membrane was designed for. The result could be a torn membrane, for which there is no repair. For example, in sea water you need 800psi to make lets say 20GPH from a water maker BUT in fresh water you could only need 250PSI to get the same production.

Some water makers regulate and control based on the output of system, while others that are using a simple pressure regulating valve (like a needle valve) to create the pressure on the system don't know or respond to the change in input water, like say a spectra would.

Making water in sea water vs fresh water requires adjustment to the pressure regulating needle valve....opps....another video by that same Boob for further details...

https://www.youtube.com/watch?v=Ht2B3lpFbdQ

[Pizzazz]

The beauty of competition for standard membranes is that one can get a new 2540 membrane from Amazon for $189. Which is peanuts in the realm of watermakers. So, feel free to experiment with clorine, urine, whatever.

Alternatively, follow Rich's advice and save the $189. My experience with membrane longetivity is with a Survivor 35 watermaker from eBay.com. it was produced in 1992, never used but maintained annually with glycol until 2002. It was kept dry afterwards. I acquired it in 2016, put the membrane in a Powersurvivor 35 and it produced water at 170 ppm (on the West Coast, 65F). How do we explain that?

[SV THIRD DAY]

Originally Posted by Pizzazz

My experience with membrane longetivity is with a Survivor 35 watermaker from eBay.com. it was produced in 1992, never used but maintained annually with glycol until 2002. It was kept dry afterwards. I acquired it in 2016, put the membrane in a Powersurvivor 35 and it produced water at 170 ppm (on the West Coast, 65F). How do we explain that?

Clean Living Paying off?
Other than that....I can't explain it...once a membrane dries out the organic layer that does the RO Magic is "supposed" to crack and fail.

Maybe the Russians had something to do with rigging it....

[senormechanico]

Rich,

From what I've read about Spectra, they don't suffer from this.
Anyway, it's worked for me for 17 years.

[SV THIRD DAY]

Originally Posted by senormechanico

Rich,

From what I've read about Spectra, they don't suffer from this.
Anyway, it's worked for me for 17 years.

Correct...Spectra doesn't use a back pressure regulating valve so they are safe to do that technique. I was warning those with other types of water makers. Sometimes people see stuff online without understanding the differences between water makers and get a surprise....

Cheers

[Tellie]

New leaf,...yeah sure, sure you are LOL. You're the same Ol Rich and I for one hope you stay that way.
I agree that proper membrane care is important for obvious reasons of trying to make them last as long as possible. I usually quote and average of 5-8 years of life expectancy of a well cared for membrane. But some membranes are an anomaly. I've had brand new ones fail in under a year. A few years ago I went through dozens of brand new membranes that just wouldn't get under 600ppms no matter what. But then I just removed a membrane last year that was 19 years old and still producing 450ppms and the owner did not do anything different than anyone else who follows recommended procedure of operation and pickling. For the most part though they give good service for years. Proper owner care of any water maker is based on knowing how and why your watermaker works the way it does. As with any boat system, the more you know the better. Watermakers are a higher maintenance piece of equipment on any boat and they can and do break on their own accord. I feel safe in saying that most watermaker issues I have seen over the years are 80% lack of proper care and understanding on the owners part. This is why having a good relationship with those that know what they are talking about is vital. Call us and we'll be glad to help. So please, don't lose my number, because getting your watermaker advice from the guy at the Tiki bar is how I pay my bills.

HaldenMarineService@yahoo.com
(954) 515-7077

[senormechanico]

My Spectra will be getting its summer workout starting this Thursday.
Just recommissioned it an hour ago.
We're going to spend 2 months in Desolation Sound, B.C. Canada. a
Back home in September.

Tellie, I'm bringing the filters !

[belizesailor]

Originally Posted by senormechanico

Rich,

From what I've read about Spectra, they don't suffer from this.
Anyway, it's worked for me for 17 years.

Got about 10 years out of my first one with reasonable care. It was still working after 10 years but TDS numbers were climbing. Had a full factory rebuild of the unit done and installed a new membrane...back to low numbers.