Reverse Osmosis filter, advice sought

(That's water to the rest of us!) Beer is about 95% water, so if you want to discuss water treatment, filtering etc this is the place to do it!
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pduk
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Reverse Osmosis filter, advice sought

Post by pduk » Mon Apr 24, 2017 9:44 pm

Hi folks,

After a number of years of reasonably successful brewing with the rock-hard water here in Hertfordshire, I want to invest in an RO filter and build up my brewing water from scratch. I have been researching RO filter systems and frankly I'm a bit overwhelmed with it all. What I'm looking for is a modest system that can be plugged into a hoselock fitting (same as for my cooler) and can give me 31-33 litres of liquor in a reasonable timescale, say 1-2 hours. I'm confused about how many stages to look for (this seems to range from 3-6) and whether I need a pump, and so on.

Has anyone bought a RO system recently and can offer advice? I'd be really grateful. Cost isn't an issue (within reason... ranges of systems I've seen so far go from £50 to £200).

Thanks

Paul.

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Wonkydonkey
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Re: Reverse Osmosis filter, advice sought

Post by Wonkydonkey » Tue Apr 25, 2017 3:19 am

The RO way is not really worth it, afais. Un less you have filthy water and want to remove some really undesirables ?
They talk in gallons per day, but I can't remember if it is usa gallons or UK gallons but if it is the former, then that's something to look at.
As for a pump, that's really down to your mains pressure. But also it will affect your out put time/volume if your pressure fluctuates. Like if you live in a block of flats and peeps have a washing machine on or run a bath.

As for number of stages. Well, that's reAlly down to your water and what you want to come out the other end.I have a 2 stage, which is some particulate filter, 5 microns. And next a carbon filter which removes chorine and a few other things that are bad for the membrane.
The membrane, is like a sock where the top end is in a tube, which is the outlet and the rest of the sock is wrapped around and a round, think of a anle sock or one of those "nice thigh-high" long socks... :wink: the former smaller surface area and a small out put per day/24hrs, where as thigh-high :wink: :wink: bigger surface area..

To add to this, RO is very wasteful, something like every 1 Lt you collect 4 or 5 Lt go down the drain.
So,,,your water meter, if you have one will be clicking away.
Back to the output.....what ever water you put in one you will get a bit out the other side. IE I got 200-caco3 water and a TDS reading of 265 and when the filers were new I got a TDS reading of 5 on the output. you can tell how good your filers and membrane are from the TDS reading, also you can get a water polisher/ion resin exchange thing to mop up the few ions that get through but unless you want distilled type water it's not worth it

so in short, you will be adding cost and time taking all those ions out and adding them back in,
But on the other hand you could dilute some RO water with tap water to get your required water style.
As for the size. Find out or just multiply the output number of (US) gallons by 3.8 (or 4.5 if it's uk) to give you Liters per day and then divide by 24 to get your out put per Hr. But that's only if it's working at its best performance.

If all else fails read some tropical/marine fish keeping forums, that's what i did #-o :wink:
Cheers
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vacant
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Re: Reverse Osmosis filter, advice sought

Post by vacant » Tue Apr 25, 2017 8:39 am

I got an RO water filter system 18 months ago because my alkalinity as CaCO3 levels are around 260 and I'd experimented with RO water bought from the local garden centre's aquarium shop which gave me the best pale beer I'd brewed, better than using loads of CRS.

COST: a 3 stage system is enough, expect to pay around £35 on eBay. I'm in an expensive water area; off the top of my head I think we pay around £3.50 per cubic metre. If I want 30 ltr I'll end up with say 150 ltr "waste water" i.e. 50p. I have no extra waste from generating RO: I bought a submersible aquarium pump for £7 and pump the waste water through my immersion chiller, though that takes twice as long to cool compared to using cold tap water pressure. The warm IC water is collected for cleaning the kit at the end of the day.

TIME: It is slow - I turn the filter on in the morning and have enough by the evening. There is no pump, just cold water tap pressure to run the filter.

MIXING: I have a salifert test kit. My water is around 255-270 I usually mix 80% RO with 20% tap then use up a bit of CRS to adjust to 30 or so.

Absolutely worth it.
I brew therefore I ... I .... forget

pduk
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Re: Reverse Osmosis filter, advice sought

Post by pduk » Tue Apr 25, 2017 4:57 pm

Thanks both for the responses, appreciated. My alkalinity is about the same as yours, vacant. I'm not on a water meter so from the money side of things I don't care, but don't want to waste water. I like the idea of using it later on through the cooler.

Paul.

Fil
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Re: Reverse Osmosis filter, advice sought

Post by Fil » Wed Apr 26, 2017 6:55 pm

also you can probably pick up 50l of RO water foc from a local aquarium supplier, our local store welcomed me in after i phoned to double check a cheeky brewer wouldnt be considered taking the yellow stuff.. i did relent and buy a token strip of ph papers while waiting for the cans to be filled tho (not a useful range for brewers either ho-hum.. ).
ist update for months n months..
Fermnting: not a lot..
Conditioning: nowt
Maturing: Challenger smash, and a kit lager
Drinking: dry one minikeg left in the store
Coming Soon Lots planned for the near future nowt for the immediate :(

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GrowlingDogBeer
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Re: Reverse Osmosis filter, advice sought

Post by GrowlingDogBeer » Wed Apr 26, 2017 9:32 pm

I'm not very technical when it comes to water, but what I do know is that if you have hard water you should put a water softener in before the RO unit as hard water seriously reduces the life of the RO membrane.

Not sure whether that will be relevant for you or not with fairly small volumes, but its a factor for me as my RO machine makes about 1000 litres of RO water a week.

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