[S. cerevisiae]

I finally broke down and purchased a small 4-stage RO unit, so that I could build water from scratch.  I was fairly disappointed with the results that I received when I ran hardness and alkalinity tests against the water produced by this filter. The filter left 42ppm hardness and 24ppm alkalinity in the water, and my water is not super hard or extremely alkaline before it enters the filter.  That's not the reduction that I was expecting.  Is there a break-in period for RO filters? 

[Stevie]

Check out aquarium forums. They have tons of info on RO systems.

[ibru]

Mark, I bought a 4 stage under the counter system last spring. I've been very happy with it. It's very slow, but I can work with that. I sent two samples to Ward and got the following results.  My water's TDS is 262 ppm, after treatment it is 24 ppm, hardness is 204 ppm, after treatment it is 7 ppm and the alkalinity is 227, after treatment it is 6 ppm. My waste goes on my lawn/hops or hay field in the winter.

I don't remember but I believe they wanted to discard the first batch (3 gallons). Good to go after that.

I would give them a call, something seems wrong.

Bruce

[mabrungard]

You should be seeing at least 95% reduction in the total dissolved solids. Some of the ions are removed at a higher rate, so the overall performance should be 95 or higher.

[beersk]

There is a very slight break in period, like you're supposed to run water through the filter constantly for 30 or so minutes after replacing filters. Either something is up with your filters or they're just not good filters. I got my TDS down to 4ppm with mine.

[S. cerevisiae]

I do not own a TDS meter at the present time, but I do own Hanna HI775 Fresh Water Alkalinity, HI721 Iron, and HI709 High Range Manganese HC colorimeters and a Hanna titration kit for combined hardness.   It appears that Hanna has finally released a fresh water version of their marine calcium hardness HC colorimeter as well as fresh water HC colorimeters for magnesium hardness and chloride.  I asked for a fresh water version of their calcium hardness meter two years ago.  Now, all we need is for Hanna to release a sulfate colorimeter.   Most brewers could get away with the HI719 Fresh Water Magnesium Hardness, HI720 Fresh Water Calcium Hardness, the HI775 Freshwater Alkalinity colorimeters.

By the way, the Hanna colorimeters are very accurate for being relatively inexpensive devices (Hanna gets you on the reagents kind of like razors and razor blades).  We recently had our water tested for a whole slew of non-brewing related compounds and organisms by a local analytical lab.  The results that came back where in line with the results from the colorimeters. 

[hopfenundmalz]

There is a very slight break in period, like you're supposed to run water through the filter constantly for 30 or so minutes after replacing filters. Either something is up with your filters or they're just not good filters. I got my TDS down to 4ppm with mine.

How high is the tap water TDS? 4 ppm is darned good!

[beersk]

There is a very slight break in period, like you're supposed to run water through the filter constantly for 30 or so minutes after replacing filters. Either something is up with your filters or they're just not good filters. I got my TDS down to 4ppm with mine.

How high is the tap water TDS? 4 ppm is darned good!

I'm probably pretty lucky in that regard, but I think I recall my tap water being 160ppm or something like that. Not crazy high.
Last I checked, the TDS was 7ppm after almost 6 months of running only brewing water through my RO system. So, still going pretty good.

[wingnut]

When I use mine, the first slug of water out the faucet has a higher PPM than you would expect.  After a few seconds, I measure again and it is back down where you would expect.

If it is not getting where you expect after running for a minute or two then yeah, something is not operating correctly.

[yso191]

I think something isn't right.  I have hard water, but not extreme.  Here is my tap water report from Ward labs followed by my RO water:

Total Dissolved Solids (TDS) Est, ppm 179
Electrical Conductivity, mmho/cm 0.30
Cations / Anions, me/L 2.9 / 3.2

ppm
Sodium, Na 40
Potassium, K 5
Calcium, Ca 12
Magnesium, Mg 5
Total Hardness, CaCO3 51
Nitrate, NO3-N 0.2 (SAFE)
Sulfate, SO4-S 3
Chloride, Cl 6
Carbonate, CO3 9
Bicarbonate, HCO3 154
Total Alkalinity, CaCO3 141
Fluoride, F 0.53
Total Iron, Fe < 0.01

"<" - Not Detected / Below Detection Limit

And here is the same report out of my under-the-sink Culligan RO system:

pH 6.5
Total Dissolved Solids (TDS) Est, ppm 8
Electrical Conductivity, mmho/cm 0.01
Cations / Anions, me/L < 0.1 / < 0.1
ppm
Sodium, Na < 1
Potassium, K < 1
Calcium, Ca 1
Magnesium, Mg < 1
Total Hardness, CaCO3 3
Nitrate, NO3-N < 0.1 (SAFE)
Sulfate, SO4-S < 1
Chloride, Cl < 1
Carbonate, CO3 < 1.0
Bicarbonate, HCO3 < 1
Total Alkalinity, CaCO3 < 1
Total Phosphorus, P 0.09
Total Iron, Fe < 0.01
"<" - Not Detected / Below Detection Limit

[mabrungard]

Steve, excepting for the alkalinity, that tap water is already fine for brewing. No RO needed. A little acid was all you needed. However, it is nice to have a clean slate for some styles.

[yso191]

Steve, excepting for the alkalinity, that tap water is already fine for brewing. No RO needed. A little acid was all you needed. However, it is nice to have a clean slate for some styles.

Good to know.  The main reason I decided to brew with RO was that the water source changes during the year.  That and I'm just too OCD for my own good sometimes.

[blatz]

Steve, excepting for the alkalinity, that tap water is already fine for brewing. No RO needed. A little acid was all you needed. However, it is nice to have a clean slate for some styles.

Good to know.  The main reason I decided to brew with RO was that the water source changes during the year.  That and I'm just too OCD CDO for my own good sometimes.

fixed that for you.

[blatz]

mark - what model did you buy?

[S. cerevisiae]

The RO filter is four-stage low-cost model from Pure Water Club.  It has a TFC RO filter.  The good news is that the lower cost RO filters apparently do have a break-in period.  I retested this evening after running the filter for 30 minutes and then collecting 6 gallons of RO water.  There was a significant reduction in hardness and alkalinity between this evening's readings the first set that I took the other day.