What is a RO filter worth?

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Talloak

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I rent a house. The previous tenants left behind a Reverse Osmosis water filter system mounted on the wall in the laundry room. My landlord told me they used it for the fish tank they had. It seems to have a particulate filter, a carbon filter, and then a osmosis membrane on the top. Looks like the $200 model found in the Midwest Brewing Supplies catalog.

I get my water from work, city water, and the local microbrewery told me they think it is good water for brewing. So I don't think I want it for myself. I am just getting into all-grain, not ready to start screwing with water. I would rather have some cash in my hand to buy other brewing stuff with.

What is this thing worth? Lucky find?
 

Bobby_M

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The problem is that you don't know how many gallons have been run through the RO membrane. That's really the heart and half the cost of a new unit ($50-80). FWIW, RO is a great for coffee.

I'd say you could probably get $60 for it. Does it come with the storage tank?
 
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Talloak

Talloak

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Haven't seen a storage tank around. Those are usually like 2 gallons or so right? They probably didn't have one, probably just ran it directly into the fish tank.

That's a free $60.
 

Schlenkerla

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RO is not all that good for all grain. It lacks the mineral content needed for beers. Its great for extract though. The total dissolved solids for RO is ~25ppm.

Be advised that its not necessarily sanitary. You can't use it as top-off water w/o risking infection. Very pure water has an affinity for attracting ions. Hence contamination can happen easily w/o proper maintenance.

Membrane filters can be replaced. I don't know how much the cost would be. I do know its the most common perishable on RO systems.

If you wanted to use it for; drinking, brewing, laundry, or cooking you should get a tank. The filtration process, reverse osmosis, is slow, very slow. It also requires 2 gallons of water to get one gallon of RO. The other gallon is lost as waste water. It needs to run continously to fill a tank. Once its full, it stops so you need to size the tank based on how much you would actually use in a days timeframe.

My $0.02 :)
 

Schlenkerla

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The value of the RO system is mainly based off the production capacity of the unit. gallons/day.
 

tipicreeper

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A short note on RO Filters.

Reverse Osmosis filters are made out a polysulfone-cellulose membrane. These membranes are clogged & destroyed by calcium & magnesium, two of the common elements that make water hard. A water softer replaces these two elements with potassium, which RO membranes can filter out quite easily.

So, using an RO system without an upstream water softener is a situation begging to have expensive RO membranes replaced frequently. Probably not as much of a problem in areas with softer waters but, extremely pragmatic in hard water areas.

On another note, RO membranes are very tight filters, in an industrial application these filters would be put into a recirculation loop as not to waste water. I have only seen a hand full of expensive home systems that use this kind of setup. Typically, (YMMV) a home system sends approximately 5 gallons of water to drain for every gallon of RO water.
Hope this sheds some light.
Cheers
-David
 

samc

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Used RO systems are not worth much IMO. If it does use a storage tank (mine does not) then without it the system won't work. You could use the housings to set up a filtration system for beer if you wanted to.

RO water is great for me. I can easily add back the missing mineral content using software and I know that I don't have to worry about Chlorine and rust, etc. BTW I have made great all grain beer without adjusting the water.
 

Schlenkerla

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A short note on RO Filters.

Reverse Osmosis filters are made out a polysulfone-cellulose membrane. These membranes are clogged & destroyed by calcium & magnesium, two of the common elements that make water hard. A water softer replaces these two elements with potassium, which RO membranes can filter out quite easily.

So, using an RO system without an upstream water softener is a situation begging to have expensive RO membranes replaced frequently. Probably not as much of a problem in areas with softer waters but, extremely pragmatic in hard water areas.
I have worked very closely with Culligan Water for cleaning glass for many years. Unless my memory is incorrect you DO NOT want a softener in line with RO. You only want to remove, not exchange minerals. We exclusively use carbon filtration before RO and our DI water treatment systems.

On more than one occasion we removed these off of our RO/DI systems and reduced maintenance costs. We contracted with Culligan and they were responsible for all maintenance. That was the first thing they objected to when they took over servicing the treatment systems.
 

springer

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I rent a house. The previous tenants left behind a Reverse Osmosis water filter system mounted on the wall in the laundry room. My landlord told me they used it for the fish tank they had. It seems to have a particulate filter, a carbon filter, and then a osmosis membrane on the top. Looks like the $200 model found in the Midwest Brewing Supplies catalog.

I get my water from work, city water, and the local microbrewery told me they think it is good water for brewing. So I don't think I want it for myself. I am just getting into all-grain, not ready to start screwing with water. I would rather have some cash in my hand to buy other brewing stuff with.

What is this thing worth? Lucky find?
Did the landlord say it was alright for you to sell it? He actually owns it now.I know I wont let my tenants remove something that was there before they moved in without my permission.
 

david_42

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I doubt you would get $20 for it. Anyone buying it would have to replace all of the elements and filters to be certain it would work.
 

Schlenkerla

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Did the landlord say it was alright for you to sell it? He actually owns it now.I know I wont let my tenants remove something that was there before they moved in without my permission.

Really good point. I didn't catch that.
 

springer

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Really good point. I didn't catch that.
I had a tenant who tried to take the water heater ... Ya he did change the 30 gallon one to a 50 himself .Good thing I was doing a walk threw when he was loading it on the truck I asked him "Did you put the old one back in" Dumb ass replied " No I tossed it and I paid for this one so i am taking it" Tossed a 3 year old electric heater my ass he sold it. Needless to say it went back in that same day.
 

Schlenkerla

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If he installs/sets it up for general water use I can't see how the LL won't mind. Its an improvement. It would need a bypass though. If it wasn't maintained you could still get some good city water through the plumbing.

If the OP goes AG I'd think the bypass is essential.
 

Bobby_M

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You could also just use it for the two 10" cartridges, one sediment and another carbon. This will benefit any brewing water. Just bypass the prefilter and RO membrane modules.
 
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