How to maintain a dormant water maker?

[Kenomac]

Originally Posted by softdown

Do tell........I have professionally installed many, many R/O systems and membranes. Adams Aquatics, thats me, has been running for 24 years now. Installing and maintaining R/O for 23 of those years.

And your professional water purification background is? Let me guess....
https://en.wikipedia.org/wiki/Desalination

Your business Adams Aquatics is very difficult to find on the internet.... actually, it's impossible to locate.

[belizesailor]

Originally Posted by softdown

Do tell........I have professionally installed many, many R/O systems and membranes. Adams Aquatics, thats me, has been running for 24 years now. Installing and maintaining R/O for 23 of those years.

And your professional water purification background is? Let me guess....
https://en.wikipedia.org/wiki/Desalination

Home RO systems right? Not salt water RO?

[Tellie]

Originally Posted by belizesailor

Home RO systems right? Not salt water RO?

Fish Tanks?

[JstaRebel]

It wouldn't matter. Cellulose Acitate membranes and Tri-Acitate which were chlorine tolerant went by the wayside many years ago, and polyamide TFC membranes which as said are NOT chlorine tolerant are the norm for freshwater, brackish water, and Seawater. And if the guy that posted that they are would like to know my profession, check www.tsgwater.com

[softdown]

Originally Posted by Cheechako

Your membrane may be shot, but often that's not a huge deal unless your manufacturer uses a proprietary one that they overcharge for. I worry a bit about leaving the pickling solution in the hi pressure pump. Will it corrode inside the piston pump?
If I were leaving a unit for a very long time I would consider removing the membrane, pickling it in a sealed bag, and flushing the system with fresh water or maybe even "safe" anti freeze left in for storage.

Pump designs vary of course. The freshwater high pressure pumps, that I have used many of, don't allow physical contact with the water as I recall. I have torn a couple apart when they quit working due to corrosion from spills. It has been awhile though. They tend to run about 100 psi....so high pressure on a much lower scale. Aquatec is the manufacturer.

I need to check if they make any pumps suitable for saltwater. I can buy Aquatecs wholesale. Big difference between 100 psi and 800-900 psi though.

EDIT: Appears their desalination is focused on giant projects: http://www.aquatech.com/wp-content/u...n-Brochure.pdf

[softdown]

Originally Posted by belizesailor

Home RO systems right? Not salt water RO?

Principle is the same. Much greater pressure is needed when working with saltwater that has ~35,000ppm TDS in the Pacific and Atlantic, 45,000 in the Middle East. Freshwater usually has less than 1000ppm TDS.

Freshwater R/O can work at ~40 psi though it works better at 100 psi or better. Saltwater R/O works well around 800-900 psi.

Anyway...looks like I got my wires crossed on chlorine and TFC membranes. I always prefilter with carbon which removes chlorine. I need to get that incorrect data removed somehow.

1-2% solution of sodium metabisulfite may be used for discouraging bacterial growth.

[softdown]

Aquatec does make a number of smaller desalination units: AQUATEC Watermaker 230/380 Volt AC

5201 Euro buys a nice 230 volt unit. Isn't that roughly 7800USD?

The membranes fed by higher voltage pumps provide a much longer life. Try for at least 110/120 volt. 220/240 volt will really put you in business.

[Lepke]

When I built my system I did everything wrong. The biggest was listen to a membrane salesman. He had me buy membranes for fresh, brackish and salt. So I have a lot of experience storing membranes. Sometimes many years. I pickle and then use a vacuum food sealer. Seems to work.

[softdown]

As may be seen by the references, aquatec watermakers are found on yachts for the common man?

Aquatec References

[softdown]

Originally Posted by Lepke

When I built my system I did everything wrong. The biggest was listen to a membrane salesman. He had me buy membranes for fresh, brackish and salt. So I have a lot of experience storing membranes. Sometimes many years. I pickle and then use a vacuum food sealer. Seems to work.

That advise was beyond horrid...as was my earlier advice. I asked mods to remove that by the way.

Anyway....refrigerating membranes will also increase storage life. Do not freeze them of course. Come to think of it, I have a couple membranes in the fridge.

Freshwater pressure: 50psi works, 100psi is much better
Brackish pressure: ~200-600psi depending on salinity
Saltwater pressure: ~ 800-900psi

As you can see, its about the pressure to make the membrane highly efficient. You do need a powerful membrane housing when operating at high pressures.

[softdown]

Sources for sodium metabisulfite:

https://www.walmart.com/ip/Pro-Cure-...lfite/48630114

https://www.amazon.com/sodium-metabi...0metabisulfite

https://www.ebay.com/sch/i.html?_odk...lfite&_sacat=0

It is a very common food preservative.

[Flyingriki]

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

[belizesailor]

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?

Will work if flushed on a regular basis. However, the problem is when the boat is unattended for extended periods...pickling is more pratical in that case.

[belizesailor]

Originally Posted by softdown

Principle is the same. Much greater pressure is needed when working with saltwater that has ~35,000ppm TDS in the Pacific and Atlantic, 45,000 in the Middle East. Freshwater usually has less than 1000ppm TDS.

Freshwater R/O can work at ~40 psi though it works better at 100 psi or better. Saltwater R/O works well around 800-900 psi.

Anyway...looks like I got my wires crossed on chlorine and TFC membranes. I always prefilter with carbon which removes chlorine. I need to get that incorrect data removed somehow.

1-2% solution of sodium metabisulfite may be used for discouraging bacterial growth.

Principle the same, but I was asking thinking there must be a diff in the membranes that makes some more chlorine tolerant than those commonly found in desalination applications.

Regardless, question answered.

[softdown]

Originally Posted by belizesailor

Principle the same, but I was asking thinking there must be a diff in the membranes that makes some more chlorine tolerant than those commonly found in desalination applications.

Regardless, question answered.

Two major types of membranes:
CTA: cheaper and less effective. Chlorine tolerant.
TFC: Not tolerant to chlorine. Has become the dominant technology especially, it seems, in desalination. Thin Film Composite......shipped dry and OK stored dry. Once wetted, it must remain wet.