Getting an RO system - have a question!

[Flip2spin23]

Point is brewing RO/Di should never set for any time ......
That's y smaller systems r allways used .. Not When needed but stored

 

[The_Bishop]

I think you are the one not getting the point. What you are talking about is *not* an issue for brewing water. There is no need to circulate the water. As far as small tanks, you *are* aware that they make RO bladder tanks up to 20 gallon capacity, and probably even larger?

As far as 'real world homebrewing', I can assure you I use what I talk about here, as do most.

I don't see what your statements about 'recirculating' an RO water storage tank have to do with homebrewing, and when pressed for details all you back it up with is some nebulous statement about how it's 'safer' and 'better'. Provide more details and evidence explaining how it's 'better' and enlighten us all.

Will RO water be different if it sits a while? Depends on the storage container! The PH may drop some due to the uptake of CO2, acidifying the water a bit, but that's not an issue for mashing because the water has little buffering capacity. The mineral content cannot change unless you have it stored in a chalk and limestone vessel. As long as the vessel is kept free of dust, debris and critters falling in I can't see how there would be any major changes that would make it unsuitable for brewing. I wouldn't want to use water that's been sitting there for a year, but dealing with that is easy; dump the tank and let it refill if you have a brew coming up and the water's been sitting a while.

 

[ajdelange]

I, and I am sure there are others here too, would like to know what happens to the RO water as it 'sets'.

 

[kickflip_mj]

I went down this road a few months ago and have been brewing with success.

https://www.homebrewtalk.com/f257/55-gallon-ro-water-tank-build-482985/

 

[nudarkshadowl]

After doing a bunch of reresearch on my own, and listening to far more experienced brewers than myself... I'm not worried about recirculating my ro water. I have a TDS meter and will check my water regularly, but I'm not to concerned about it as it will always have a lid on it.

 

[Flip2spin23]

I'm no water guru , I have no exact explanation of y to recirculate the RO water ... I just know when I purchased/installed our 15,000 gpd RO/DI system. The hired engineer made a point to pass thur a uv light and recirculate the system if is sat not running more that 5 hours. Strictly to keep consistent water daily . Also the vents on the storage tanks all have .4 micron filters to keep any thing from entering the system ...
Like I Said in earlier post its probally overkill in a homebrewers setting
My .02 If I can dig up some of the testing we did on sitting RO/DI water I will post it

 

[ajdelange]

The explanation was given in #28 with respect to pharmaceutical, semiconductor and other plants with ultra pure water needs. A brewery is not a pharmaceutical or semi conductor plant. It has none of the stringent requirements for ultra pure water and, therefore, 'polishing loops' are not used nor are they required. A straight RO system does not reduce ion content to the level that justifies their use. The only place you might find and RO system with polishing loop in a brewery is in its lab if that lab has an ultrapure water supply. These are typically small benchtop units (for a small lab) and they include ion exchangers in addition to RO cartridges (if they have RO cartridges - some are designed to be fed from a lab or plant's RO system).

If you find test data the most dramatic thing it will show is that resistivity gets well below the 18 MΩ-cm requirement for ultra pure water. In a typical bench top system there will be a resistivity meter. In order to dispense you turn on the circulation pump (the dispenser is attached to the polish loop) and watch the meter. Resistivity rises as the ion exchanger takes out the bicarbonate ion and when the tops 18 you can take water. When finished dispensing you turn the pump off and CO2 starts working its way in by diffusion so that next time you go to draw water the resistivity is low again. In a RO only system this loop isn't there. Resistivity never approaches 18 MΩ-cm. What would you recirculate through? A TOC filter and past a UV light I guess if you were concerned about TOC and particles to the extent that a phamaceutical or semiconductor manufacturer is but a brewer isn't concerned about those things. A brewery does not need ultrapure water and so does not install an ultrapure system. A brewery does not recirculate its RO water.

 

[Buckeye_Hydro]

RO, and RODI water absolutely do have a different taste...

You'll not want to push RODI water to a pressure tank - somewhat counterproductive to do it this way. It's easy enough to send RO water to the pressure tank, and RODI water to the reservoir, (our Reef/Residential RODI systems are designed to do just that) if that will meet your needs.

Russ

 

[elerten]

In regards to home built RO water systems. Make sure to stay with stainless or proper plastic type fittings for anything in contact with the water for any length of time. Especially if it's deionized. Deionized water really wants minerals in it. It will corrode and erode damn near any metal it comes into long stationary contact with. I deal with ro/di water all the time and it even eats the concrete if there is a leak somewhere and it dribbles on the ground for a couple days. For brewing it's not an issue but to get to a low endotoxin level it requires heat. We boil so it's not really an issue, but even ro/di water can have/grow endotoxin type stuff. We test all our drops weekly for specifically this.

 

[bja]

RO, and RODI water absolutely do have a different taste...

That's BS.

You'll not water to push RODI water to a pressure tank - somewhat counterproductive to do it this way. It's easy enough to send RO water to the pressure tan, and RODI water to the reservoir, (our Reef/Residential RODI systems are designed to do just that) if that will meet your needs.

Russ

Were you drunk when you posted this?

 

[ajdelange]

RO, and RODI water absolutely do have a different taste...

That's BS.
....
Were you drunk when you posted this?

That's a little harsh. They might taste different if there were a problem with the RO system or if the RO water was saturated with oxygen and CO2 (sat in an atmospheric tank) and the DI water were really DI, 18 MΩ water subject to TOC filtration etc. I'd want to see the difference detected in a triangle test, though. One data point: the RO water and DI water here taste the same - flat.

 

[bja]

That's a little harsh.

You're right, that was harsh and I apologize.

They might taste different if there were a problem with the RO system or if the RO water was saturated with oxygen and CO2 (sat it an atmospheric tank) and the DI water were really DI, 18 MΩ water subject to TOC filtration etc. I'd want to see the difference detected in a triangle test, though. One data point: the RO water and DI water here taste the same - flat.

This is the point I was trying to make in an earlier post. If everything is working properly, there will be no detectable difference, at least to your palate. I've been using a RO/DI for 15 years. I've drank both and could never tell any difference.

 

[Roadie]

I used to keep a stony reef tank for a number of years and used DI water for that, however for the line that I ran to our refrigerator/ice maker I split it off after the RO and before the DI. IIRC the tap gave me around 150 TDS water which the RO took to about 4 TDS water and the DI dropped to 0. I decided to not drink DI water after reading about it stripping electrolytes from your body to which some people are more sensitive than others. I read about some people suffering headaches, shaking and having dry skin and it just wasn't worth it to me to determine if any in my family were sensitive to the effects of DI water or not when I considered RO to be pure enough and way better than our tap water. For every person who said it bothered them it seemed there were 10 saying they never had an issue but again it simply wasn't worth the experiment to me. YMMV.

 

[Buckeye_Hydro]

Not drunk - just in a hurry.

I've worked with RO and RODI water for 20 years, and the taste difference between the two is obvious. Maybe this is not true with all feedwater. We've run across instances before where people couldn't tell the difference - in almost all cases they we're using mis-configured ebay RODI systems where the DI water passed through a carbon bed.

Russ