RO Water in Cold Liquor Tank

[IAW]

Is anyone aware of any issues related to having RO water sitting in a cold liquor tank for 24 to 48 hours?

My water treatment guy is concerned.

Thanks

[jwalts]

Is he concerned about microorganisms funkifying the water? In terms of mineral content, you shouldn't have any problems unless your cold liquor tank is made of limestone and you're pressurizing it with CO2 . Seriously, though, I'm curious to know what your water treatment guy is worried about.

Joe

[dberg]

Is he concerned about microorganisms funkifying the water?

Since the water is not protected by chlorine, that is a definite concern

[IAW]

RO water

His concern is the acidity of the RO water being in contact with stainless steel for more than a couple of hours.


I would assume that all breweries have de-chlorinated water sitting in hot and cold liquor tanks, which you sanitize on regular basis.

[TNbrewer]

From talking to some of my colleagues over the years who employ RO in their treatment programs, corrosion is a very real concern.

From the Water Quality Assoc. website, http://www.wqa.org

"..Reverse Osmosis-treated water is aggressive to metallic pipe or to substances that can ionize and dissolve in water—not because of low pH (acidity), but because it is highly pure and has few dissolved substances in it.
.....Water is called the universal solvent; it always "wants" to have substances dissolved in it. The less it has, the more aggressive it becomes in attacking things that can dissolve. This doesn’t hurt the human body, of course, because our physiology quickly obtains homeostasis using saliva, stomach fluids, etc. to equilibrate all bodily fluids.
.....However, with plumbing materials, inert plastic piping—not metal piping—is recommended for contacting all very high purity waters."

Joseph F. Harrison, P.E., CWS-VI

Cheers,
Travis

[IAW]

RO water

Thanks Travis, seems like his concern is legit.

[liammckenna]

Here in St. John's, the city actually adds some temporary hardness to the water because it is so naturally soft. Apparently such soft water is extremely corrosive, even to stainless steel.

Pax.

Liam

[jwalts]

I learned something new today. Thanks!

[Moonlight]

Yes, but it depends on how extreme you RO the water. If very pure water ,called "aggressive water, it is best to add a bit of mineral (or un-RO-ed water) to DI/RO water sitting in stainless or other metal tanks.
If you intend to use pure water only occasionally, you would likely already have some mineral scale on the tank walls which would accomplish this. The stainless blend of 316 would have better resistance than the milder 304.