[redzim]

Thinking about getting an RO system for my brewing needs as I blow through a lot of distilled water at $1 a gallon....  I have a very mechanically minded friend helping out, he works with a lot of contractors and knows some companies that install RO systems.   I know next to nothing about RO systems and he knows nothing about brewing. He told me to price out a system they need to know what end result of water I want coming out of the system.  I said, as close to distilled as possible, but apparently that is not the answer they are looking for. What water specs should I be telling them I need? Ideally I'd like very close to distilled, and then add gypsum and CaCl and epsom, etc, back in to brew pale beers...  any suggestions from folks who have RO systems?

tx red

[rabeb25]

You want 0 TDS water. You can get away with a 75gpd membrane, and a DI canister. A Storage tank or 2 is a good thing.. I run 2-15 gallon storage tanks. I run the air water ice-typhoon 5...airwaterice.com

[yso191]

Yes, my understanding is that the difference between distilled and RO is academic.  I have an RO system and use it for 100% of my brewing water.  I use Brun' Water for determining additions.  I highly recommend it.  The only advice I'd have is to be sure you also have a charcoal filter in the system to remove chlorine, etc.

[kramerog]

I think DI (deionization) and 0 TDS (total dissolved solids) is overkill.  DI is laboratory grade stuff.  I don't spec RO systems so I'm not sure where the price points vs. specs are.

[mabrungard]

No! You definitely don't want zero TDS water for brewing. That is a waste of time and money to treat water to that level and then add back ions for taste. In most cases, starting with a low level of ions is OK. In fact, most large brewers know that a low level of ions is OK and they use a higher efficiency process called nanofiltration that actually leaves a little more of the ions in the treated water and it saves water and energy compared to RO.

There is guidance on the Bru'n Water facebook page regarding RO systems. You'll need to go way back in the articles, but look for: What RO System should I Buy?

Enjoy!

[redzim]

Martin, I found your article, thanks...

So what would be an acceptable TDS... less than 25ppm? Or what numbers should I be saying I want out of my system: zero alkalinity? zero bicarbs? zero total hardness? or all those "as low as possible"?

[Joe T]

My RO system comes from freedrinkingwater.com. It's a little pricier than the ones at the big box stores but it works great. The RO membrane has a 10 year warranty and at 6 years old my water goes in at >350ppm and comes out tasting fresh and clean at ~15ppm. The RO membranes from the big box stores only have a 3 year warranty so I would have replaced mine twice by now.
It's a great investment if you have crappy, hard, chlorinated water like me. We use ours for everything: drinking, cooking, houseplants, pets, and of course brewing. But for brewing, do get a larger holding tank.

[mabrungard]

Less than around 50 ppm TDS is a decent starting point. As an example, Pilsen water typically has a TDS of around 30 ppm. So ultra low TDS is definitely not necessary or desirable. In most cases, a home RO system will produce much lower TDS than that. An important factor for success is occasionally monitoring the TDS content of your system to tell when the membrane is going south.

With regard to treated water quality from a system, its unnecessary to seek zero on any of them. Even with the single digit value you can obtain for most ions in a RO system, you are likely to want more of some ions in a quest to improve the flavor of the water and the resulting beer.

Say NO to zero...when it comes to brewing water quality.

[ynotbrusum]

I installed the RO system with a 20 gallon tank and TDS meter on both in and out. My water comes from my softener (installed on cold side per the mfg. directions) at ~350 ppm and comes out at ~10-30 ppm.  I will be sending a batch to Ward for analysis to confirm the readings, but I have been building from the meter readings.  I don't know how many processed gallons I will get from my filters, but friends tell me you just watch the TDS and change if the number rises significantly or every six months.

[redzim]

Less than around 50 ppm TDS is a decent starting point. As an example, Pilsen water typically has a TDS of around 30 ppm. So ultra low TDS is definitely not necessary or desirable. In most cases, a home RO system will produce much lower TDS than that. An important factor for success is occasionally monitoring the TDS content of your system to tell when the membrane is going south.

With regard to treated water quality from a system, its unnecessary to seek zero on any of them. Even with the single digit value you can obtain for most ions in a RO system, you are likely to want more of some ions in a quest to improve the flavor of the water and the resulting beer.

Say NO to zero...when it comes to brewing water quality.

We're going forward on this and getting firm quotes on RO systems...  so Martin, if I spec something like <50ppm TDS, and single digits on all ions like Ca, Na, Mg, Cl, SO4, etc, that would be reasonable?

And what about alkalinity and bicarbs?

And what about pH, do I need to worry that the pH of RO water is slightly acidic?

thanks
red

[ynotbrusum]

We're going forward on this and getting firm quotes on RO systems...  so Martin, if I spec something like <50ppm TDS, and single digits on all ions like Ca, Na, Mg, Cl, SO4, etc, that would be reasonable?

And what about alkalinity and bicarbs?

And what about pH, do I need to worry that the pH of RO water is slightly acidic?

thanks
red

[/quote]

I believe RO presents no RA, Bicarbonate or pH issues, since it has been stated that if you use RO for sparging, you don't need to treat it regarding pH concerns.  Based on that, I build my strike water from RO and sparge with straight RO - but caution should be used if you are not batch sparging or no sparge brewing.  Fly sparging can extract tannins, if you get too low on the gravity (below 3 Brix, IIRC).