Storing ro membrane in preservative

[heus]

I have always stored my membranes in the machines. This year I would like to store my membrane in a separate canister in the house so I dont have to heat my ro room. My question is can I just place the membrane in the storage canister, mix up preservative in a bucket with distilled water, and dump it into the membrane/canister? I would like to skip the recirculation of the preservative through the wash tank while still in the ro if possible.

[Fun4stuff]

I will just be storing mine in the membrane housing filled with preservative. I’ll connect bottom outlets of the housing with the top inlet using a Tee connector as shown below. No need to reinvent the wheel by glueing pieces of pvc together 😁:D

https://imgur.com/a/4bMWS9q

[BobMac]

What preservative do you use? new to the ro this year. read after doing rinse, soap, rinse, acid, rinse, soap and final rinse
that some just use premate or distilled water to store for the summer.

[eustis22]

Preservative = Metabisulfite Sodium

[Fun4stuff]

I will just be storing mine in the membrane housing filled with preservative. I’ll connect bottom outlets of the housing with the top inlet using a Tee connector as shown below. No need to reinvent the wheel by glueing pieces of pvc together ��:D

https://imgur.com/a/4bMWS9q

It’s my first year too!! I’m just doing the trees in my yard. Made about 1.5 gal of syrup. So i think I’m relatively small time and didn’t put as much stress on my membranes as others doing a lot more.

I read about those extensive wash/rinsing too. Also seems to be a lot of people that just store them in distilled water in their fridge. I may just do peroxide (2 quarts peroxide per 3 gallons warm water) and rinsing. Then store in sodium metabisulfite solution (1.1 oz per gallon) (i already have it from beer and wine making).

[Gord]

I have the same question. Seems like people store their membranes differently. Some in preservative and some in water.
The end of season storage instructions for my set up says to flush with preservative but rinse and store in water.

[smokeyamber]

Jumping on the question of storing as well.. I have a 4 membrane setup and was wondering if anyone stores their membranes in preservative in a 5gallon sealed bucket ? I was going to make some tubes for storing, but thought the bucket would be just as good. Then next season I rinse them out prior to using them.

The idea of storing in the fridge after a wash is out not an option due to space ...

Getting close to having to have a solution for this year, but hopeful to get some more syrup in after this warm spell.

[Sugar Bear]

I will just be storing mine in the membrane housing filled with preservative. I’ll connect bottom outlets of the housing with the top inlet using a Tee connector as shown below. No need to reinvent the wheel by glueing pieces of pvc together :D

https://imgur.com/a/4bMWS9q


This seems like a good idea. But one of the concerns I have is how PVC stands up to metabisulfite sodium over time.

I have been told by people that know something about it that it probably suffers some decomposition over time when it is exposed to MS, whether it is DWV or PW-G rated.

With that in mind I would rather decompose some pvc I glued together rather then my pvc housings which I will then be running my sap through.

But then again perhaps your clever idea will have no issues, at least none detectable anyway.

I.E. the metabisulfite sodium preserves the mebranes we can safely assume, but can we also safely assume it preserves PVC?

[Gord]

Seems like most are storing their membranes in preservative. Why would my directions say to store it at years end in water? Now I'm questioning it?

[carls47807]

Hey Gord,

Which directions are you using for end of season storage?

[Gord]

This is what my directions say from Carl.

Instructions for End of Season Storage
For end of season storage, flush according to Instructions for Cleaning” section 5, step 2.After you have completed the flush, prepare 1 gallon of warm water (~80F), and dissolve our membrane preservative in it (as per the instructions on the bottle)
Recirculate the gallon of solution through the system for 30 minutes.
After 30 minutes, turn the unit off and let it sit for a couple of hours to a day.
After that, pull the intake suction hose and allow the unit to run dry.
Reinsert the intake suction hose into clean water and rinse the system for 2 minutes (approximately 2 gallons).
Remove the prefilter from the filter housing. If storing a bucket system, leave the lid off and make sure the unit is
completely dry (leaving the membranes full of water).
Do not let the pump sit in a humid environment during storage.

[littleTapper]

I've followed Carl's directions and the membranes kept just fine so I followed them again this season :) 2 gallons of permeate after the preservative isn't going to flush every bit of it out either.

[Sugar Bear]

Seems like most are storing their membranes in preservative. Why would my directions say to store it at years end in water? Now I'm questioning it?

I will also store my membranes in preservative, Metabisulfite Sodium specifically.

However it does not take a lot of it to kill a person. Consuming about half an ounce will kill a person, 99 out of 100 times apparently.

It is toxic and somehow we loose track of of that.

I know of a large commercial producer in Vermont who just uses water to store there membranes and say they never have problems. Even though they sell Metabisulfite Sodium.

Now I am questioning why I am using Metabisulfite Sodium.

[Fun4stuff]

This seems like a good idea. But one of the concerns I have is how PVC stands up to metabisulfite sodium over time.

I have been told by people that know something about it that it probably suffers some decomposition over time when it is exposed to MS, whether it is DWV or PW-G rated.

With that in mind I would rather decompose some pvc I glued together rather then my pvc housings which I will then be running my sap through.

But then again perhaps your clever idea will have no issues, at least none detectable anyway.

I.E. the metabisulfite sodium preserves the mebranes we can safely assume, but can we also safely assume it preserves PVC?

I've been making beer and wine for 20 years and used metabisulfite as a preservative and no rinse sanitizer for many of those years (before StarSan came along). I've kept the solution in plastic jugs for years without issue (unlike StarSan which is acidic and will eventually break down plastics). I'd have to do more research though to be sure. But I doubt it has any real effect on PVC over 1 year.

[Sugar Bear]

I've been making beer and wine for 20 years and used metabisulfite as a preservative and no rinse sanitizer for many of those years (before StarSan came along). I've kept the solution in plastic jugs for years without issue (unlike StarSan which is acidic and will eventually break down plastics). I'd have to do more research though to be sure. But I doubt it has any real effect on PVC over 1 year.


Yes I would doubt it to.

But my point is why let your RO canisters sit in it all season with the membranes and the metabisulfite solution. When you can just let the membranes sit in a alternatively ( and easily ) made PVC canister with the metabisulfite solution.

I would let as few chemicals as possible sit in my RO system components as possible over the period of 1 year. Considering we will be running hundreds of gallons of concentrate ( waste water ) over that surface ( The PVC canisters allow for a lot of waste water contact of the PVC surface ) Not so much of the permeate flow.

Its just sending out more invitations to the unknown and asking for the unexpected.

A lot of sugar makers will not even put there membranes in metabisulfite solution.

They may well know something we don't, so frankly I don't blame them.

[Fun4stuff]

Anything in the right concentration or amount can be lethal, including water. As far as where sodium metabisulfite goes, it’s relatively safe, having been used in the food industry as a no-rinse preservative for years

[Sugar Bear]

Anything in the right concentration or amount can be lethal, including water. As far as where sodium metabisulfite goes, it’s relatively safe, having been used in the food industry as a no-rinse preservative for years

Yes, but the point I am making here is that the best and safest thing to store your RO components in over the off season is good old fashion air. Unless necessity dictates something else as it does for the membranes.

With that said I will store my ,membranes in a metabisulfite sodium solution over the next 10 months.

I have been told by a LARGE commercial producer in Vermont that they store there membranes in the refrigerator, with water in a tightly sealed plastic bag. Even though they sell metabisulfite sodium.

They say it works for them and it is one less chemical that has a very high toxicity level completely out of there equation for them.

While I believe the term "Organic" is a case for the nut jobs, I like to keep reality within the equation ... "Metabisulfite Sodium is toxic when ingested in small quantities and also is known to form a corrosive acid when mixed with water" ... so why put it in contact, for 10 months, with RO components that it does not have to be in contact with? PVC housings... check valves ... polyethylene tubing ... whatever?

I have noticed that according to Gord and Carls directions he does not even store the membranes in the metabisulfite sodium over the summer. Just rinses them with it and stores with water.

I'll bet Carl knows something about this that I don't. Probably a few others as well.

Da Bear

[DrTimPerkins]

But one of the concerns I have is how PVC stands up to metabisulfite sodium over time.

I completely agree that it is great to use as little toxic material as possible or a less toxic substitute if there is a good alternative.

Most membrane makers and maple equipment (RO) manufacturers recommend the use of SMBS as a preservative. Most commercial maple producers I've talked with store their membranes in PVC cannisters with SMBS. Our membranes are sent in our membranes each year for cleaning and that is how they come back.

The chemical resistance of PVC to SMBS is generally considered to be excellent/high.