RO Water Worries

I have only ever used RO water for mixing my Starsan solution but am about to try doing Kai's Edel Hell recipe using RO water.

Went to my local RO Water machine and purchased 30L of RO water. Decided to make up 4L of Starsan solution and put the other 26L aside waiting for my WLP830 to arrive.

A week passed and I happened to look at the unused 4L of starsan solution and was shocked to see it had gone as cloudy as I have ever seen Starsan go after months of use.

I contacted the company who own the machines and had a good discussion with the manager who said all the right things and is sending me free tokens to compensate for my inconvenience. He admitted that filters and membranes etc do deteriorate and that clearly there was a problem with the particular machine and they would rectify it without delay. He will SMS me when it is back to 100% efficiency and I will shoot down and load up with pure RO water.

My concern is what my beer may have turned out like if I had not made the starsan solution. I have a ph meter on the way but frankly would not have a clue about water chemistry and what sort of things caused the solution to go cloudy.

Seems the moral of the story is - do not blindly believe the water coming from the RO machine is all it is cracked up to be.

It's the hardness in water that causes the cloudiness. So, that water must have had a fair bit of mineralization.

For a few bucks you can buy a conductivity tester that reads estimated TDS. You want RO water that reads less than about 10 mg/L.

Thanks AJ
Silly questions but would the cheap chinese testers be usable and do the probes have a short life like the pH meters?

These should be good enough. Probably a good idea to zero them before use in some distilled water (note: the 'distilled' water I just bought here is labeled as having TDS < 5 ppm) before use.

No, the electrodes on these don't degrade as long as they are kept clean (and some don't even have electrodes but I don't think that will be the case in this price range).

Thanks AJ.

I agree with AJ. A TDS meter is a fairly simple apparatus and there is little reason why you can't get an adequate measurement with an inexpensive unit. I think I paid $30 for a dual-probe in-line TDS meter from HMI.

I got this one a year or so ago for buying water from RO machines and it works fine. Chose it because it was cheap and calibrated with solution aboue 350 ppm TDS vs many at 1000 ppm TDS. It also reads in the 0-5 ppm TDS in distilled water.

http://www.amazon.com/dp/B000VTQM70/?tag=skimlinks_replacement-20

I just bought water recently and went out of the way to get a sample from the store's water supply. I took a dixie cup and got a TDS reading of 430ppm from the bathroom tap (consistent with a Wards report I did a few years ago with my unsoftened house water). Water from the RO machine was about 20ppm TDS (95% difference from what I assume the source is). The grocery store machines always read in the 15-30ppm TDS range here.

I also brew with commercial RO water. The place where I buy gets certified every year. The owner is going to send me the test results of their last certification. It's worth asking.

As far as the StarSan and the cloudiness. I have found no link between cloudiness and actual pH stability. I have very hard tap water and my StarSan turns cloudy quickly. I've stored some for several months and pH test strips indicated that it hadn't degraded.

The Glacier machine at the neighborhood grocery has a display that tells you when the machine was last serviced, a TDS probe could still be a good cross check.

Well I received my cheap Chinese TDS meter today and tried it out on the 4 water samples I currently have in the house.

Rain water from our storage tanks (pumped to laundry) = 10 ppm

Tap Water from local city water system = 360 ppm

Water purchased from nearby charity fountain drawing water from an aquifer under local brewery (probably filtered) = 59 ppm

RO water from an RO Water machine at local shopping complex = 60 ppm


Is the RO water up to standard?
Would I be better using out abundant supply of rain water instead of RO water?

I've brewed with rain water before. The beer was great. It's as close to distilled as you get naturally. I'd go for that if you have an abundance of it. Obviously you'll want to add back calcium, chloride, and sulfate (you might only want sulfate for hoppy beers though).

I think I will try the rain water for my next brew which is going to be Kai's Eden Hell. I will add 5gms of CaCl2 to the 20L batch.

Assuming you'll be using pilsner malt and not many other adjuncts...I'd also try 2% acidulated malt if you can find it.

el_caro said:

Rain water from our storage tanks (pumped to laundry) = 10 ppm

Tap Water from local city water system = 360 ppm

Water purchased from nearby charity fountain drawing water from an aquifer under local brewery (probably filtered) = 59 ppm

RO water from an RO Water machine at local shopping complex = 60 ppm


Is the RO water up to standard?

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It might or might not be. Given that the municipal water runs 360 ppm you would expect RO water from a properly maintained system to be less than about 18 ppm unless the operator is putting some minerals back in for taste as some do. In either case 60 ppm TDS is probably something you could work with but it's not what one thinks of when talking about RO.

el_caro said:

Would I be better using out abundant supply of rain water instead of RO water?

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It is certainly lower in TDS than the store 'RO' water and if your goal is to start with a 'plain sheet of paper' then yes, the rainwater might be a good way to go. The only concern I'd have with rain water from storage is what else might be in there besides a low level of minerals. I have in mind organic things like rotting gallah carcases or some such. I note that you seem to use this water for laundry only. If the storage system is well protected from animal incursion then I suppose there would be little reason to worry.

The other thing I would think about a bit is what makes up those 10 ppm . If you live near a metropolitan area there might be quite a bit of nitrate and sulfate from automobiles, factories etc. A low pH would indicate such a potential problem but with TDS of 10 even nitrates shouldn't be a problem for you. If you live in Katherine or some similar place then you probably would not need to worry about this. But then in such a locale you wouldn't have an abundant supply either. Perhaps my concerns are more relevant to the States than Oz. You still have few enough people/autos down there that 'acid rain' may not be a problem for you - yet.

Thanks For the input everyone
AJ we have a new colorbond roof and a clean as can be hoped for rainwater storage and reticulation system. Certainly no dead birds and animals can enter the storage as there are 3 different fine mesh filters on the inlet line to the tanks.

The plumber was not keen on having the whole home on the pump as we only have 10,000 litres of tank space and he figured it is not a good idea to be switching on the pump dozens of times a day for small volumes. The Laundry seemed the logical place to use the water and the garden.

We live about 50 meters from a minor arterial single lane road with constant stream of vehicles - nothing like your freeways here.

No obvious air pollution in Adelaide generally and certainly not in our area, so I figure not much concern there with nitrate and sulphates.

I wonder if it is worth considering installing a filter on one tap from the pump to clear out any of that 10 ppm before using it for human consumption?

el_caro said:

The plumber was not keen on having the whole home on the pump as we only have 10,000 litres of tank space....

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That says that if you had a larger tank that he would not have and objection and that implies that the rain water is quite suitable for drinking and thus brewing.

el_caro said:

No obvious air pollution in Adelaide generally and certainly not in our area,...

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No indeed. Lovely town (and surrounding area too).

el_caro said:

I wonder if it is worth considering installing a filter on one tap from the pump to clear out any of that 10 ppm before using it for human consumption?

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Ten ppm is virtually mineral free, the minerals are probably sodium and chloride (from salt particles carried aloft from the gulf) and therefore not of concern. Most filters wouldn't remove them anyway. If there were dust or pollen then a particulate filter would get rid of those but not the dissolved stuff.

Thanks again.