I feel a little silly posting this, but I’m ignorant of this topic. My local Wal-Mart just installed an RO Water dispenser. $1.85 for five gallons… Paying a $1.85 verse fetching spring water to brew is an easy trade off. I understand that RO water is a great starting point to brew. But here’s my question… Is all RO water the same? Or should an analysis be conducted on this water?
RO will have a small amount of minerals. How small depends on the feed water and the filter condition. You could be fine without testing, but if you are like me your curiosity will get the best of you.
I have to ask, did you ever get the spring water tested? That could help you decide. Spring water can be very low to very high in minerals.
I have not. I’ve not really gotten into water chemistry. That water made better beer than our well water. I was about to get our well water tested until I found this little gem at Walmart. The spring I was getting the water from is 20 minutes down the road and filling 60 gallons at a time is a PITA.
$1.85 for 5 gallons is a good deal! Sounds like its time to dabble in some water chemistry… 
+1. At the very least, assuming the store’s RO machine filter is in good shape, you’ll be getting more consistent, cheaper water, Frank. I bought a fairly cheap TDS meter like this one to check the water each time before I buy it. So far the water from the store I buy from has tested great every time.
I bought a TDS meter too. Just because.
I have been building from grocery store bought RO for the last several batches. It’s nice and cheap and gives me a better idea of my starting point. After reading HoosierBrew’s suggestion on another thread, I also bought a cheap TDS meter. Have not brewed since I bought it though. My water softened tap water read somewhere in the 130 range though. Glad I’m using RO!
So the RO reads what - let others know for comparison.
Yes. What should RO read?
Pretty low. The stuff I bought from a store the next town over was 12 ppm TDS and all of the nrewing ions were
<1 ppm. That was from ward labs, - for the record.
I also use RO water from the machine in the store and am happy with it. I usually blend with tap water, the ratio depending on what I’m brewing. But for the lightest beers, I use 100% RO and build back up.
Also, it doesn’t hurt to have a couple 5-gallon jugs of potable water around in case of apocalypse.
Yeah, my last brewing RO was ~ 16 TDS with all the brewing ions < 1.5 ppm IIRC. The thing is, you could tell if the store’s filter/membrane were past needing changed if you tested and it was suddenly 80 or 100ppm TDS. The manual with my meter said that RO should pretty much always be < 25ppm TDS.
;D
Sorry. I have not brewed since I bought the TDS meter, so I have not checked any RO water levels with it yet. I’ll let you know when I do though
My old mid price pH meter did not cal up the last brew day, so it was time to get a better one (Milwaukee 101 this time). Pulled the trigger on a TDS meter at the same time.
When I switched from spring water(~100 ppm tds) a few years ago to RO(~350 ppm in and ~15 ppm out) I knew nothing of water chemistry. I used straight RO with nothing added for the first several batches, ranging from light to dark and malty to hoppy. They all just tasted dull and boring. Unless you’re brewing a bopils, you’ll want to at least add some gypsum and/or calcium chloride. Water chemistry can be rather intimidating at first but a basic familiarity of what kind of water makes good beer and the ability to use an online water calculator will get you there quicker than you think. The Brun water’s water knowledge page is a great place to start. When you taste that first IPA brewed with water with a good amount of sulfates, you’ll be hooked!
+1. i have new RO system and the water is fairly stripped clean. i check with TDS meter regularly also.
Hey, as long as it’s consistently stripped clean, it’s a good base to build on ! I envy the RO system but not the $$ now. Someday.
I here ya. I really didn’t have much choice considering my well water is so high in bicarbonate and 114ppm sodium (naturally soft) that it took so much lactic acid to get the ph to shift lower…one of my early brewing frustrations I’m glad I’m done with.
this is why i installed an RO system.
my well water:
pH 8.0
Total Dissolved Solids (TDS) Est, ppm 283
Electrical Conductivity, mmho/cm 0.47
Cations / Anions, me/L 5.3 / 5.4
ppm
Sodium, Na 114
Potassium, K 2
Calcium, Ca 4
Magnesium, Mg 1
Total Hardness, CaCO3 14
Nitrate, NO3-N 0.1 (SAFE)
Sulfate, SO4-S 3
Chloride, Cl 3
Carbonate,CO3 6
Bicarbonate, HCO3 297
Total Alkalinity, CaCO3 253