Preserving RO Membrane with Silver Oxide

[Tellie]

Originally Posted by funjohnson

I don't see it written often enough... Tellie, your help is much appreciated on this website. If it wasn't for your postings, I don't know how much I would have spent on watermaker mistakes.

Thanks for your time,

Matt

Thanks so much for the compliment funjohnson, I enjoy your posts as well. I'm one of those twisted individuals that really likes his work and enjoys helping others, especially here on CF.

[dennisail]

Originally Posted by Tellie

Just a note. Be careful with using anything other than the factory recommended pickling solution. If you use standard sodium MB on your Spectra system please, please, call me. I'd love to sell you a new Clark pump at $3,600. But seriously, the best advice is phorvati's. PG-100 is the way to go. It will not only store your membranes longer than any of the powdered mixes, it will help lubricate vital internal components and help seals, O-rings, valves etc. to remain in good state. Remember the large percentage of powdered storage solution is either product water or distilled water. This water can be corrosive over a period of time. SodiumMB will pickle your membrane but does have slight degrading effects on the membrane each time it's used. In an Oxygen deprived environment like is found inside a pickled watermaker that sits for months on end nasty things can happen. Like your pre-filters, the pickling solution is not an area to all of a sudden go cheap on for a few supposed dollars savings. Every season I get the same calls two days before they want to go to the Bahamas from people that bought a 10K watermaker that they figured they'd save a $10-$30 on by buying cheap pre-filters and using some other storage solution other than what the manufacturer recommends. Save the cheap SodiumMB for making the beer and wine and when it's finished and ready for consumption Call Tellie up, invite him over for a six pack or two and chances are good he'll bring you the right storage solution for your watermaker, even trade.

Thanks for the reply. This thread is getting better.

My whole system only cost $2300, but i'm not one to save $10 to risk my whole system. What is the generic name (or Australian equivalent) for PG-100. Is it just ethylene glycol? Can I use anything from the auto parts store, or will the radiator additives also have other chemicals which will be bad for the system?

[witzgall]

Tellie a good guy. To clarify what he wrote, if you have a Spectra watermaker, and use the same powdered pickling solution (MB) that is used on most other brands of watermakers, you will DESTROY your clark pump.

Chris

[GordMay]

Originally Posted by dennisail

... What is the generic name (or Australian equivalent) for PG-100. Is it just ethylene glycol?
Can I use anything from the auto parts store, or will the radiator additives also have other chemicals which will be bad for the system?

PG-100 is an inhibited PROPYLENE GLYCOL based industrial heat transfer fluid and antifreeze that contains food grade corrosion inhibitors, and is suitable for use in potable water systems.

* “Pro-Tek PG-100" Manufactured by DiversiTech
MSDS ➥ http://media.diversitech.com/doc/DOC32442.pdf

➥ Product - DiversiTech

Automotive anti-freeze, even if PG, is NOT suitable.

[Tellie]

Gord as always is correct.

dennisail, This needs to be very, very, clear Ethylene Glycol is deadly. Propylene Glycol -100 is what we are speaking about.

[Tellie]

Originally Posted by witzgall

Tellie a good guy. To clarify what he wrote, if you have a Spectra watermaker, and use the same powdered pickling solution (MB) that is used on most other brands of watermakers, you will DESTROY your clark pump.

Chris

I'll take the "Good Guy" status

My writin, spellin, and explanation skills have my English teacher mother winching in pain.

[noelex 77]

Tellie is one of the good great guys on CF.
He always gives fantastic advice on watermaker operation.

That is one Scary avatar he has , however.

[dennisail]

Originally Posted by GordMay

PG-100 is an inhibited PROPYLENE GLYCOL based industrial heat transfer fluid and antifreeze that contains food grade corrosion inhibitors, and is suitable for use in potable water systems.

* “Pro-Tek PG-100" Manufactured by DiversiTech
MSDS ➥ http://media.diversitech.com/doc/DOC32442.pdf

➥ Product - DiversiTech

Automotive anti-freeze, even if PG, is NOT suitable.

Thanks for clarification. I will try to find it.

[belizesailor]

Originally Posted by Tellie

Just a note. Be careful with using anything other than the factory recommended pickling solution. If you use standard sodium MB on your Spectra system please, please, call me. I'd love to sell you a new Clark pump at $3,600. But seriously, the best advice is phorvati's. PG-100 is the way to go. It will not only store your membranes longer than any of the powdered mixes, it will help lubricate vital internal components and help seals, O-rings, valves etc....

So, I find myself in a bit of "pickle". All those nice little white containers of white powered turned out to be cleaning compound NOT storage compound. I could of swore I had plenty aboard, but apparently not.

Now, I am about to leave the boat for 6 months....

I looked at the MDS for Spectra's storage solution and it appears that the active ingredient is just good old Boric Acid (cheap and readily available almost anywhere on the planet).

So, do I mix up a mild Boric Acid solution or go on the search for a solution like PG-100? Or, as many do, just fresh water flush and leave it (I like this solution least).

[belizesailor]

Asked the same question of Spectra and here is the official reply:

Only Propylene Glycol based R/V Antifreeze is compatible with your Spectra Watermaker. There are three known suppliers of high quality PG based antifreeze; West Marine, Amsoil and Bright bay. Customers need to be aware that not all RV Antifreeze is PG based and some suppliers are labeling their antifreeze as EITHER Propylene Glycol or Ethyl Alcohol and Glycerin mix.

Only PG (or PDO) is approved for use in Spectra Watermakers. Propylene Glycol should be used at a concentration of at least 25% to achieve the desired effect as a biocide or mixed per the label instructions for the required level of freeze protection. Remember your system has between 1.5 and 4 gallons (Ventura 150 to Newport 1000 respectively) in it so take this into account when calculating the mix. When pickling the watermaker you will need to take the water in the system into account when calculating your mix ratio. After you have completed a fresh water flush, there about 2 gallons of water in the system, so if you need a 50/50 mix you will need 2 gallons of antifreeze in your pickling bucket. If you need the concentration to be higher than this you can start with the antifreeze in a bucket and put the brine discharge in a separate bucket. Turn the pump on and run until you see antifreeze and then shut it off. You will now have as much of the water out of the system as possible so you can recalculate your mix ratio. No you can't use just Boric Acid.

[zboss]

What are membranes made of? Sodium Metabilsulfate is used in the brewing industry, or more to the point, the wine industry for two purposes:

1) It removes chlorine from public water supplies through a chemical reaction
2) It kills most bacteria without killing yeast while waiting for wine to start to ferment

If the membranes are just spun nylon (or something like that) then there are may be much better modern chemicals that are completely food safe (you can drink them out of the bottle) that might be able to be used. For example, we use SaniClean (http://www.fivestarchemicals.com/wp-...cleanTech1.pdf).

[colemj]

With Spectra, it is not the membrane that is the issue, it is the Clark pump and its components, which only Spectra uses. Sodium Metabisulfate is harmful to their pump, not their membranes.

Mark

[zboss]

Plastic has to be the worst invention ever... it breaks down when you don't want it to and it never breaks down when you do!

I am not saying you should - you should probably call your manufacturer - but we do use the sanistar in plastic buckets for months at a time without it destroying the plastic. It comes in concentrated liquid form in a HDPE container.

Does the clark pump use a specially formulated plastic?

[noelex 77]

The inportant message is Spectra watermakers should not use sodium metalsulfide as a preservative as it damages the Clarke pump.
The correct chemicals are not expensive, especially when they are needed rarely.

Don't use incompatable chemicals is a simple message that is not difficult to comply with.

Btw in concentrations used to pickle the watermaker membrane sodium metalsulfide produced a severe skin reaction on me (and I don't react to anything else), so take some precautions.

[belizesailor]

Originally Posted by belizesailor

Asked the same question of Spectra and here is the official reply:

Tried to find P. G. here in Panama...no joy. Really like the option of using it, but demand for a food grade anti-freeze is pretty limited here in the tropics and thus so is availability.