Reverse Osmosis Seems Slow and Wastes Water- Really Needed for City Water?

[micraftbeer]

I've been brewing for many years using Distilled Water purchased from the grocery store or Target. I'm way past the point of being tired of it and am in the process of converting my basement "homebrew storage area" into my "electric indoor brewing area". I've put in some plumbing for a dedicated tap to hook up to what I had planned for a Reverse Osmosis system.

However, while researching this, I see they typically make 3-4 gallons of waste water for every gallon of RO water. That seems pretty wasteful.

And the flow rate on most systems is about 3 gallons of RO water per hour. So even my typical small 2.5 gallon batches will need almost 2 hours of water collection. And I'm not really that patient.

I live in the Detroit area, and our tap water generally speaking is pretty good right out of the tap. I was thinking I could probably get away with a simple single stage or dual stage filter set-up and eliminate the waste water and speed up the throughput.

Anyone else do the same? What water contaminants are the most critical that wouldn't be taken care of already with city water processing?

 

[PodunkPorter]

Depends on your homebrew taste standards, and on the beer your making, and on what's in your water. I would at least pass it through some charcoal. Or just go buy 10 gallons of RO at Walmart for 3 bucks and add some minerals accordingly

 

[Yooper]

RO removes minerals and reduces bicarbonate/alkalinity to near 0. Detroit water may or may not be high in minerals and alkalinity. Can you call the water supplier and get the water test results for calcium, sulfate, sodium, chloride, magnesium, and bicarbonate? And ask if they use chlorine or chloramine for disinfectant? If you can, we can definitely advise you.

I couldn’t get that info where I live, so I send in a water sample to Ward Labs. At that time, it was $18 for a water report, but currently it’s a about $26.50 and they will tell you all you need to know.

Some tap waters are great for brewing, and some are terrible for brewing. Knowing what you are starting with is the only way to know which you have.

 

[z-bob]

The water here tastes good but is terrible for brewing. Most people buy RO water from the co-op (they maintain their machine better than the supermarkets) I've taken it as a personal challenge to brew with tapwater.

The folks that have their own RO machine say to put it after the water softener. It's counter-intuitive, but the softener pulls the calcium, magnesium, and some iron out of the water and replaces them with sodium. The RO system then pulls the sodium out, and the membrane will last a lot longer than if you fed it with hard water.

 

[micraftbeer]

City of Detroit most recent water report: http://www.detroitmi.gov/Portals/0/docs/DWSD/Water Quality Reports/2016 water_quality_report_web.pdf

Calcium: 29.5 ppm Average (2.1 - 98.5 max/min ppm)
Sulfate: 23.8 ppm Avg (17.5 - 33.4 ppm)
Sodium: 5.17 ppm Avg (3.56 - 7.23 ppm)
Chloride: 0 ppm Avg (0 - 0 ppm)
Magnesium: 9.52 ppm Avg (7.71 - 12.56 ppm)
Bicarbonate Alkalinity: 76 ppm Avg (66 - 86 ppm)

Chlorine Residual monitored in the distribution system: Quarterly results range 0.53 - 0.93 ppm (running annual average for prior 4 quarters 0.83 ppm)

A quick read from Palmer's How To Brew book on reading a water report (http://howtobrew.com/book/section-3/understanding-the-mash-ph/reading-a-water-report) it looks like the above numbers are pretty good. The Bicarbonate might be high if I'm going for some Pilsners, per his guidance. And I know from personal sniff tests of the water, from time to time I can smell hints of chlorine.

So I definitely would want a filter that can deal with chlorine. Not sure if there's something that would deal with Bicarbonate? Or if there are other considerations?

 

[mongoose33]

I've been brewing for many years using Distilled Water purchased from the grocery store or Target. I'm way past the point of being tired of it and am in the process of converting my basement "homebrew storage area" into my "electric indoor brewing area". I've put in some plumbing for a dedicated tap to hook up to what I had planned for a Reverse Osmosis system.

However, while researching this, I see they typically make 3-4 gallons of waste water for every gallon of RO water. That seems pretty wasteful.

And the flow rate on most systems is about 3 gallons of RO water per hour. So even my typical small 2.5 gallon batches will need almost 2 hours of water collection. And I'm not really that patient.

I live in the Detroit area, and our tap water generally speaking is pretty good right out of the tap. I was thinking I could probably get away with a simple single stage or dual stage filter set-up and eliminate the waste water and speed up the throughput.

Anyone else do the same? What water contaminants are the most critical that wouldn't be taken care of already with city water processing?

Forgive me, but what do you pay for water? Even if there is 4 gallons of waste water for every gallon of RO, that means if you collect 4 gallons of RO you'll have gone through....20 gallons?

Is your water so expensive that this 20 gallons is worth more than the aggravation of buying and hauling distilled water from the store?

There are many ways to do RO water. I now have mine more or less permanently installed, but the system is the same.

'

I originally hung my RO unit on the wall in the garage so that if I had to I could bring it in during very cold weather. I drew supply water directly off the faucet spout. I dump the RO water into a 7-gallon Aquatainer. Drilled out the vent hole to 1/4", the output line fits it perfectly. I just let the thing run during brew day, collecting water for the next time.

I've since mounted it more or less permanently below the sink, and have a permanent line plumbed in below.

You could do the same thing--store RO water in an Aquatainer so it's ready the next time you want to brew. Collect more while you brew, and it's ready again for the next time. And the cost? Unless you're paying rather dearly for 20 gallons of water out of the tap....

 

[divrack]

I got used to amazingly clean spring water on tap here in West Scotland that was basically pilzen water then moved to somewhere that is taken straight from a river with a bunch of chlorine dropped in it and I can't drink the stuff let alone brew with it. Ro water is pretty great for me. Cost a hundred bucks or so, but there isn't exactly water shortages in Scotland.
However for most purposes you'd probably be fine with a couple filters. I think carbon is the one for chlorine.
It can be a pain in the arse if you haven't let a bucket or two fill beforehand. Sometimes I just go and fill my boiler from a burn on the hill to get a nice local terroir.

On the other hand ro water is scientifically proven to protect you from the dreaded chemicals and 99 percent of evil cia alien satellite signals

So in short it is great for some, but not everyone. Youd probably be fine with just filters unless your palate is really good. On the other hand if your favorite beer is pilsner id go ro

 

[micraftbeer]

Thanks for the replies. Just to clarify what I'm after, as it seems I may not have done a good job of explaining that.

1. I don't want to buy my water from the store any more. Whether it's distilled or RO from a store, I don't want the extra step of hitting the local store to buy my brewing water (or forgetting to...).

2. Researching RO systems, they ALL have waste water. It's part of the process. The membrane of a particular system/manufacturer will dictate your ratio of waste water to RO water. If you're looking to pay $70 - $100 for a system, the ratio (from my short research) is about 4 gallons waste to 1 gallon RO. The best on the market is a 1:1 ratio where 1 gallon of RO creates only 1 gallon of waste water. That system costs $600. While I might be able to convince myself that dumping a gallon of water down the drain for each gallon of brewing water is less environmentally bad than driving to the grocery store and buying all of my gallon jugs of RO water, no way I'm paying $600 for that system. And I'm not comfortable with dumping 4 gallons of water down the drain in the name of my greater beer pursuits. I did the math based on my water bill and I pay $0.01/gallon. So it's not an economic issue of dumping the water.

3. So this leaves me with other water filtration systems that aren't RO, and hence don't have any waste water. But I need to get pickier about what types of filters I use to get rid of just the stuff that's going to cause me issues. I won't have that 100% clean slate starting point like I've grown accustomed to and add my salts accordingly. But as long as the base water doesn't have too much of any one thing, I can then just "top it off" with some brewing salts.

So I'm looking for guidance on #3.

 

[divrack]

You'd probably be fine with a 1 micron filter and an activated carbon one.

 

[mongoose33]

Well, we all get to choose what values drive our lives. I give my spent grains to a friend who has chickens, rather than just dumping them in the woods behind our house. Makes me feel better.

There will be waste with almost everything. My RO system does have rejection water, but ask yourself this: where and how are they getting the RO water at the store? What waste goes into producing distilled water they sell?

IMO, the closer I am to the beginning of the process, the less overall waste there will be. No miles on my car, no gasoline burned, no time wasted.

But--everyone is free to make their own determinations. Perhaps brewing simply has too much waste for you to be comfortable. Perhaps the only answer is to give it up.

 

[z-bob]

Does the waste water have to go down the drain? Couldn't you recover it in a bucket and use it to flush or something? (which technically still goes down the drain, but...)

BTW, the water report in post #5 looks pretty good. Why would you want to filter it?

 

[JohnSand]

Heat removes the chlorine in water.
Here on Long Island, tap water makes great beer.

 

[mirthfuldragon]

I've been brewing for many years using Distilled Water purchased from the grocery store or Target. [...] However, while researching this, I see they typically make 3-4 gallons of waste water for every gallon of RO water. That seems pretty wasteful.

First, your water seems pretty decent, so using Bru'n Water or the calculator of your choice should let you get pretty close to what you need in most circumstances. Other than taking precautions against chlorine (a carbon filter or time), I expect you are fine. I use Chicago tap water (dechlorinated but rock hard) for most of my beer, unless I am working on a NEIPA or something else that requires significant adjustments. You probably don't *need* RO water.

Also, I think the waste water from an RO filter is a much, much smaller environmental sin than buying jugs of water at Target.

 

[schematix]

just curious how much water you 'waste' cleaning all of your brewing equipment? how much do you 'waste' chilling?

RO water isn't sinful when you consider that you use vastly higher amounts of water on things like showering, washing the dishes, flushing toilets, etc.

 

[lump42]

You'll want to check with the water district whether they are using chlorine or chloramine. Many municipalities are moving towards chloramine because of increased stability within the water, which incidentally means it won't dissipate over night or boil out of the water. The only way to treat it is with a charcoal filter with enough contact time. OR you could use metabisulfate to chemically break both chlorine and chloramine down. End products will be sodium or potassium ions (depending on Meta source), chloride, and sulfate. The reaction happens within a few minutes so not really any more prep time. Don't remember the exact usage, but I use have a tablet for strike and the other half for sparge water.

I would just use the tap water straight no filter and add the campden tablet. If you want to do a pilsner or something that needs really soft water, you could use the ro water to dilute your tap water.

I definitely understand minimizing waste. It's why I use a cooler of ice, a gallon of water, and a pond pump to chill. It cuts my chilling water down to under 5 gallons. The ice was going to be made and just melt in the machine over the weekend anyhow.

 

[Yooper]

Exactly! Find out if it's chloramines (likely) or chlorine. Either way, a crushed campden tablet in 20 gallons of water will remove it, but heat and charcoal filters won't remove chloramines- at least not in the timeline and contact time used in home filtering or boiling.

For pale beers, you will need to reduce the alkalinity via acid like phosphoric acid, and all sparge water should be acidified, but your water is decent and can be used with those two caveats.

 

[davealicious]

save the waste and use it for cleaning, watering plants, etc. plenty of great uses for ro waste water. invest in a system that produces the amount of water you usually brew with over the course of a day. for me thats a 50gpd RO setup. i turn mine on 24 hours before planned brew day, along with my yeast starter.

EDIT: prior to doing this, i'd buy two RV Carbon Block filters from home depot, hook them up in series to the outlet of a garden hose and use that. generally did a pretty damn good job, and i think they're rated for like 3000 gallons or something so a pair of them would last me a year or so. link: https://www.amazon.com/dp/B0006IX87S/?tag=skimlinks_replacement-20

 

[GrizzlyBier]

RO removes minerals and reduces bicarbonate/alkalinity to near 0.

When you use RO water, don't you have to add brewing salts back in to achieve your desired profile? Or do you just brew with RO? What's the difference between RO and distilled?

 

[z-bob]

When you use RO water, don't you have to add brewing salts back in to achieve your desired profile? Or do you just brew with RO? What's the difference between RO and distilled?

Last question first: RO water is like poorly-distilled water. Different process to get kinda the same thing. It still has some dissolved salts, but much less than the input water. And more than distilled or deionized water.

Whether you have to add salts back in depends on what style beer you are brewing, A Czech pilsner? probably not. When our club does a "big brew", everybody brings 5 gallons of RO water and we add salts back. But the water here is terrible. The craft breweries here (the good ones) have their own RO machine and mix RO water with dechlorinated city water, and probably don't have to add much salts but maybe a little (again, it depends on the beer style) I don't know how they dechlorinate it; probably a carbon block filter.

 

[Jayjay1976]

I'm on chicago water so I don't filter and just use 1/2 campden to dechlorinate, my beers turn out fine. I'm brewing mostly ales and when I want to brew a lager I just spring for bottled spring water; ice mountain, etc. It's still cheaper than buying beer, right?

 

[micraftbeer]

I use Distilled because then I know/assume that gives me a 0 in all the various mineral categories for mashing/brewing. Then when I want to go match some water profile someone puts out there, I just look at what I have to ADD to match that. If I was starting with water that had too high of Calcium levels and I wanted to try out a profile that wanted lower Calcium, I'd be out of luck.

To some degree, I guess I approach it like hops. I add the different types of hops I want to produce the desired effect, at different times in my process. I'm starting with 0 hops, so that's easy to control. If for some reason I was using pre-hopped wort, it may or may not work for a particular recipe.

For me, it looks like my city water profile is already pretty good/low on the key minerals, so I'm going to use some charcoal filters to ensure I don't have extra chlorine in there, then I'll sample my post-filtered water and get it tested. That will then be the building block for whatever water salt adjustments I want to do.

For me, that's what I'm after. I get that for some people they're fine going other routes. I was just trying to come up with a way to use my water from the house, but not do Reverse Osmosis.

 

[mabrungard]

If your municipal water system is drawing from the Great Lakes, the tap water should be a good alternative for brewing. Carbon filtering at low rate or using campden tablet, are solutions for removing chloramine from the water. Since the flowrate through a filter needs to be crazy slow, I suggest that campden tablet treatment is actually surer and easier.

You'll still need to adjust that tap water, that isn't too hard when you have the minerals and acid. There is plenty of software that can assist you in determining how much of those components you'd need to add for each brew.

 

[Dcpcooks]

You can buy a chloramine charcoal filter from buckeye hydro. The key is slow flow. If you go too fast it won’t be effective. Your water will work for most all beers sans pils and light lagers. You’ll still need to acidify for ph and sparge water.

 

[kylevester]

According to the water quality report you linked to, Detroit pulls from Lake Huron, Lake St. Clair inlet, and Lake St. Clair effluent (near Lake Erie). The Lake Huron plant is in St. Clair County and would serve that surrounding area.

The 0 ppm of Chloride is a little dubious, I'd expect more along the lines of 10-20 ppm given the levels we see in Lake Michigan and the use of road salt and softeners all around this area. Low, but I doubt it's 0 ppm.

You've got a large range on your hardness ions, but a pretty stable alkalinity. Depending on the brew, you'll need to add acid to knock it down a bit or alkalinity to bring it up (malt bills with lots of roasted malts). Overall, it's pretty good water and will work just fine. Is it perfect for every style? Nope, but it'll work fine.

I may recommend CaSO4 or MgSO4 to adjust your sulfates and CaCl2 or NaCl to adjust your chlorides. I wouldn't use both CaSO4 and CaCl2 to adjust given the range of calcium reported.

I'd use campden tablets to remove the chlorine/chloramine. No extra filtration is required, but won't hurt it if you use it.

 

[ScrewyBrewer]

I've put in some plumbing for a dedicated tap to hook up to what I had planned for a Reverse Osmosis system.

However, while researching this, I see they typically make 3-4 gallons of waste water for every gallon of RO water. That seems pretty wasteful.

Not all RO flters are the same. The SpectraPure CSP RO 90-AF filter I have uses just two gallons of water to produce one gallon of pure RO water.

 

[Yooper]

When you use RO water, don't you have to add brewing salts back in to achieve your desired profile? Or do you just brew with RO? What's the difference between RO and distilled?

You don't HAVE to add brewing salts. Think of it like "seasoning" for the beer. Plain RO water may be fine for some beers (like someone else mentioned Czech pilsner), and it won't hurt if you don't add salts to other beers but the beer might be blander than if you had added some. Just like you add salt to chicken soup to enhance the flavor, you add brewing salts as desired because of the flavor impact.

You can get by with gypsum, calcium chloride, and lactic acid if you want to be a minimalist. That's all I use 99% of the time.

Distilled can be used as well- it's just more expensive for me. They are close enough to be interchangeable in brewing. Distilled has 0 of everything, while RO as very very low numbers, but not always 0.

 

[Buckeye_Hydro]

Not all RO flters are the same. The RO filter I have uses just two gallons of water to produce one gallon of pure RO water.

Realize that YOU can control the ratio of concentrate to permeate (aka waste water to pure water).


This ratio is affected by your water temperature and your water pressure, and is controlled by a little $4 part called a flow restrictor. The traditional ratio of 4:1 you may have heard of comes from the RO membrane manufacturers. But remember that that recommendation was established with absolutely zero knowledge of your particular water. So...
If you have municipal tap water low in total hardness, or have a softener, you can typically go with a lower ratio. There are no magic membranes that won't build up scale if you over-restrict them.

Russ

 

[shoengine]

just curious how much water you 'waste' cleaning all of your brewing equipment? how much do you 'waste' chilling?

RO water isn't sinful when you consider that you use vastly higher amounts of water on things like showering, washing the dishes, flushing toilets, etc.

Good point. Why bother increasing efficiency of the brewing process if you are going to just end up showering and using the restroom?

 

[davealicious]

Realize that YOU can control the ratio of concentrate to permeate (aka waste water to pure water).


This ratio is affected by your water temperature and your water pressure, and is controlled by a little $4 part called a flow restrictor. The traditional ratio of 4:1 you may have heard of comes from the RO membrane manufacturers. But remember that that recommendation was established with absolutely zero knowledge of your particular water. So...
If you have municipal tap water low in total hardness, or have a softener, you can typically go with a lower ratio. There are no magic membranes that won't build up scale if you over-restrict them.

Russ

you can increase your flow restriction, but I would recommend a quick flush of the membrane afterwards to help get any excess build up rinsed off. this is done by removing the flow restrictor and allowing ALL of the water to go down the waste for a brief while. Common practice for those keeping saltwater reefs who often use an RO/DI system for infrequent use, much like brewing. not sure why the practice never took off with home brewers.

 

[ScrewyBrewer]

Realize that YOU can control the ratio of concentrate to permeate (aka waste water to pure water).


This ratio is affected by your water temperature and your water pressure, and is controlled by a little $4 part called a flow restrictor. The traditional ratio of 4:1 you may have heard of comes from the RO membrane manufacturers. But remember that that recommendation was established with absolutely zero knowledge of your particular water. So...
If you have municipal tap water low in total hardness, or have a softener, you can typically go with a lower ratio. There are no magic membranes that won't build up scale if you over-restrict them.

Russ

I'm not sure what your point is? My source water is low in TDS and my filter has an automatic membrane flush feature built in.

 

[davealicious]

I think the point is that you can control the ratio. It's not about the membrane, its about the flow restrictor and design of the system. Your system uses an Auto Flush and a high pressure flow restrictor, thats why it produces a 2:1 ratio instead of the typical 3 or 4:1 ratio. the use of a higher restriction at the flow restrictor has a tendency to clog membranes, well, your system has an auto flush to help rinse the membrane.

As i said, lots of reef keepers manually flush their membranes to prolong the life. Thats what your system is doing.

hell, you could just plug the outlet and it would provide a 0:1 ratio until the membrane becomes totally clogged. at which point you could attempt to flush it and possibly get some more life out of it.

its a simple trade off.

 

[ScrewyBrewer]

I think the point is that you can control the ratio. It's not about the membrane, its about the flow restrictor and design of the system. Your system uses an Auto Flush and a high pressure flow restrictor, thats why it produces a 2:1 ratio instead of the typical 3 or 4:1 ratio. the use of a higher restriction at the flow restrictor has a tendency to clog membranes, well, your system has an auto flush to help rinse the membrane.

As i said, lots of reef keepers manually flush their membranes to prolong the life. Thats what your system is doing.

hell, you could just plug the outlet and it would provide a 0:1 ratio until the membrane becomes totally clogged. at which point you could attempt to flush it and possibly get some more life out of it.

its a simple trade off.

Ahh got it and thanks for explaining. There is a timer on my RO filter or a flow meter that automatically triggers the flush cycle after every ~20 minutes of steady use. And I remember when installing the filter the instructions called for inserting a flow restrictor based on the pressure of the source water at the inlet.

 

[mongoose33]

Ahh got it and thanks for explaining. There is a timer on my RO filter or a flow meter that automatically triggers the flush cycle after every ~20 minutes of steady use. And I remember when installing the filter the instructions called for inserting a flow restrictor based on the pressure of the source water at the inlet.

Every 20 minutes? Wow.

I have an RO system, but I let it run for hours as it fills the aquatainer I use. I flush it at the beginning of use, and again at the end. But not every 20 minutes. I wish I had a system that would do that for me. But there's only so much money, and I have other more pressing brewing items on my need/want list.

 

[davealicious]

I wonder @ScrewyBrewer considering the flush frequency are you actually getting 2:1? is that counting the flush water?

I'm with you @mongoose33, I use a 35 gallon rotomold container and fill with water as a holding tank, I use a RO/DI system and its helpful to have 35 gallons on hand for brew days, or for my saltwater reef tank. I've thought about installing a UV light inside the tank to kill off anything that hangs out in there but generally i run it empty then refill when i'm gone for a weekend as i found out that my 75gpd system cannot produce 75 gallons in a day, i'm much close to 25-30 per day but thats starting with water with a TDS content around 450.

 

[ScrewyBrewer]

I wonder @ScrewyBrewer considering the flush frequency are you actually getting 2:1? is that counting the flush water?

I'm with you @mongoose33, I use a 35 gallon rotomold container and fill with water as a holding tank, I use a RO/DI system and its helpful to have 35 gallons on hand for brew days, or for my saltwater reef tank. I've thought about installing a UV light inside the tank to kill off anything that hangs out in there but generally i run it empty then refill when i'm gone for a weekend as i found out that my 75gpd system cannot produce 75 gallons in a day, i'm much close to 25-30 per day but thats starting with water with a TDS content around 450.

Honestly I've never bothered to check it, looks like the auto flush runs every hour. I plugged in the SpectraPure CSP RO 90-AF reverse osmosis water filtration system and took their claims at face value.

 

[day_trippr]

fwiw, my autoflush does an 18 second flush once per hour...

Cheers!