Water to Flush RO?

[SeanD]

I got a Deer Run RO this summer and Ray said that I have to flush it with untreated water before I use it. In the winter, I only have access to town supplied water that's been chlorinated. What do other people do to flush their RO in the winter? I'd hate to blow the first 100+ gallons of sap for the season just to flush the membrane.

Sean

[Dennis H.]

Do you know of any family member or friend who is on well water?

[JoeJ]

I attended a RO talk this past spring given by Steve O'Farrel from Memprotec where he explained that you should not use sap to rinse your membrane in the spring. He estimated that you lose 10-15% capacity by rinsing with sap. He stated that you should use water low in iron and manganese and water that is relatively soft. (and no water with chlorine in it). I tested my well at the sugar house (very hard water with lots of iron) and the well at my house, 3 miles away. Luckily, the house water is low in both iron and manganese and relatively soft. So I will be hauling a couple loads of water from home to do the spring rinse.

[CharlieVT]

I am also wondering about flushing preservative with well water rather than using first run sap.
There are relatively inexpensive meters that will tell Total Dissolved Solids (TDS meter) which give a non-mineral specific
reading of the hardness of well water.

I found this chart of hardness on the net:
Degree of Hardnes................ Grains per Gallon (gpg).................. ppm (or mg/L)

Slightly Hard........................1.0-3.5 ..............................................17.1-60
Moderately Hard ................. 3.5-7.0 ........................................... 60-120
Hard .................................7.0-10.5.............................................1 20-180
Very Hard............................>10.5 ................................................ >180

If I get one a TDS meter and check my well water, what degree of hardness would be acceptable or unacceptable to use
for flushing the RO? I realize it is a matter of degree, but seeking opinions from experienced RO users. Or is the type of mineral so important that
TDS isn't a meaningful measure?

Thanks in advance for your replies.

[JoeJ]

Charlie,

I had my water tested at the State lab. Steve Ofarell told me that rinsing a RO membrane with water that is high in iron and manganese will really mess it up. He said that my water was OK to use with a total hardness of 4 and iron content of <.10 mg/L and manganese at .013 mg/L. At first I had only the iron and manganese test done and Steve said that the over all hardness test was important in the final analysis.

For the past 8 years I just followed the instructions for my Lapierre RO and rinsed out the storage solution in the spring with 600 gal with the 600 gal machine and then 1200 gal of sap with the 1200 gal machine. OUCH!! Dumping some of the highest sugar content sap of the season down the drain was always depressing. That 1200 gal of sap this spring would have made 24.5 gal of syrup. I really won't mind spending 3 hours to load (and transport 3 miles, 2 trips) 1200 gal of cheap water.

Joe

[SeanD]

Thanks for the feedback. I'll ask around to see who is on well water and see if I can work something out with them. Does a typical homeowner with well water know the hardness of his/her water? or how much iron or manganese is in their water?

Sean

[JoeJ]

Most home owners would most likely not know what the iron / manganese content of their water was unless the water was causing hard water problems like staining toilets, dishwashers and laundry problems.

[maple flats]

I believe some RO owners have rinsed their RO with chlorinated city water that was soft. The way to do it is to haul enough water to do the job, and put it in a SS tank (a clean sap tank?) and let it set for 3-4 days so the chlorine evaporates out, then use it. This is exactly how I did mine back in 2011 and I let it set for a week. Then I used it to rinse the RO. Remember, you may need less water than you think. As you rinse you can run the permeate discharge back into the tank to use it again, after maybe 10 minutes running. All you need to discharge is the concentrate as you rinse.

[MapleMark753]

I'm aware of the prohibition of using chlorinated water directly through a membrane, not good for the membrane. But like maple flats said, it does break down over a pretty short period of time. We've had to haul chlorinated town water this summer due to the drought, and the smell is pretty much gone after 2-3 days, but haven't measured for residual chlorine. Also the RO's that are sold for residential usage (very small ones) often have an activated carbon filter which is designed to remove the chlorine from the water before it hits the membrane. Don't know what an activated carbon filter attached say to an outdoor residential spigot would do, but it would be fairly easy to test the resulting water with a chlorine tester. I saw that Ray's water at his place was pretty hard (red filter pretty quickly) but he did rinse with that. I have one of his 125 RO's too. Not saying to DO any of the above, but it may be worth taking a look at to see if its feasible or possible. Just a couple thoughts.
take care, Mark

[Urban Sugarmaker]

I agree with all the thoughts on using chlorinated city water. At Verona in January 2016 the CDL rep did a talk and took questions on flushing for pre-season. He said water right out of a garden hose is fine. Also, he indicated chlorinated water is fine but you will still need to flush that out prior to operating under pressure. The real danger comes from operating the membrane under pressure with chlorinated water. Myself, I plan to let about 100 gallons of city water sit for a few days, then flush it through. I am confident I won't destroy the membrane. It's just plain old chemistry that the chlorine dissipates when the water is sitting open to air.

[40to1]

Hopkinton should have an analysis of your water (and/or MWRA water). As Urban Sugarmaker said, have your 100 gallons sit in a barrel for a few days. The chlorine will dissipate.

[hodorskib]

Not that I am a fan of putting any chemical through a system - but this is a product I use for my fish tank since I have city water - removes chlorine
https://www.amazon.com/API-Tap-Water-Conditioner-16-Ounce/dp/B001EWFUSK/ref=sr_1_2?s=pet-supplies&ie=UTF8&qid=1479684488&sr=1-2&keywords=dechlorinator&th=1

[SeanD]

Good ideas and a chemistry lesson to boot. I'll have to time that strategy so the barrels don't freeze up. How long can the RO sit flushed and preservative free before I use it for sap? We usually get a January thaw before the real season gets going in mid-Feb (although the last couple of years the tap date has been all over the place). Is that too early?

Sean

[CharlieVT]

Not that I am a fan of putting any chemical through a system - but this is a product I use for my fish tank since I have city water - removes chlorine
https://www.amazon.com/API-Tap-Water-Conditioner-16-Ounce/dp/B001EWFUSK/ref=sr_1_2?s=pet-supplies&ie=UTF8&qid=1479684488&sr=1-2&keywords=dechlorinator&th=1

Careful!

RO membranes are not fish. Whatever is in this product, it isn't going to remove iron and maganese molecules from the water. All it can possibly do is bind these chemically to make them "non-toxic" to fish.

The info about this product states: "The active ingredient in this, sodium thiosulfate..."

So now you have added sodium thiosulfate, not to mention other unlisted "inactive" ingredients. I wonder what that might do to a RO membrane.

Conceivably, adding this product to tap or well water and then flushing a RO with it could be much worse than using the water alone.

https://en.wikipedia.org/wiki/Sodium_thiosulfate#Neutralizing_bleach.2C_chlorina ted_water.2C_and_related_treatments

[Bricklayer]

I got a used 4" membrane from a friend of mine that washes windows. It's only ever seen well water. I rinsed it a couple times then acid washed it a couple times and rinsed again. All with well water. Got it back to about 95%. So my plan is to use this membrane for making permeate for the initial flush at the start of the season. And if I get in a bind and run out of permeate during the season. I bet you could get a used membrane or a real cheap one to make some permeate.

[Super Sapper]

Sodium Thiosulfate is use to remove the chlorine not hardness. A softener replaces Calcium and Magnesium with Sodium.

[DrTimPerkins]

I agree....best not to try any chemicals that "bind" the iron, chlorine, or other ions in the water. That will simply convert the free chlorine into a bound form....it doesn't actually remove it.

Leaving city water in an OPEN container will reduce the chlorine levels, but not totally eliminate them.

There are fairly inexpensive deionizing cartridges or pre/post-filter activated carbon filters that should work to make your water fine to flush the RO. We use them for pretreating water before it runs into the deionizer for pure water in the lab. There are also home filters that'll do the same thing. Cheapest place is probably through some hot-tub (spa) supply company for pretreating water for use in a spa. All of those work quite well and most decent units will remove 99+% of the ions. Flow rates are fairly slow though, so basically you need to hook them up and let them run for a day to get enough water out of them.

You DO NOT want to use any of these filters with maple sap or maple syrup though. That's a big no no.

[SeanD]

That's great. Thanks, Doc. I've come across a number of different filters and cartridges. These (below) are designed for spas and RVs and have garden hose adapters. They claim to remove chlorine and iron. Is this something like what you were talking about?

http://www.thriftyapplianceparts.com/wsrv-8-inline-rv-water-filter/

https://www.amazon.com/dp/B01D57CVEM/ref=psdc_1273008011_t2_B00AXP8B9O

Thanks,
Sean

[DrTimPerkins]

Yes. Those would work. Be sure to use food-grade hose to connect it up (not a regular garden hose). Flow will be quite slow, but that is good in this case.

[SeanD]

Fantastic! Thanks so much.

Sean