Food for thought.....using your "reverse osmosis" system

[Bugeater]

The salts go down the drain. As water passes over the membrane, only a portion of the water passes through. The rest of the water flows on to the overflow and flushes the salts away from the membrane on the way. It wastes water but is the only economical way to avoid clogging the membrane.

Wayne
Bugeater Brewing Company

[BrewTa2]

Down the drain. The purer water passes through the membrane, much of the salts are swept away with the effluent:

The membrane eventually clogs up, they can be backwashed to some extent.

[boobookittyfuk]

ahhhh....i see!

the only thing i didn't understand was the actual house hold RO system design. Our system in the lab has 100% through put. So i naturally figured that house hold system was the same.

even that picture shows that its not 100% effective. But then who gives a shit if you are off by 5-10 ppm with your brew water anyway? You almost need a lab grade scale to measure out salts to add back any way.

[Stomatopod]

It really just depends on your rejection rate and water pressure. You can get a very low rejection rate but you have to use high pressure. I use a high rejection rate and pre-filters to keep the membrane working properly, also a back flush helps the life of the membrane as well. Also if you are worried about the content of your water get a TDS meter. They aren't that expensive, and there are even ones that you can run in-line so you can see your before and after TDS.

-G

[SoCal Surfer]

God Damn! R U kidding me? I thought I was golden just hitting my strike temp right on. Now I have to worry about this shit. I refuse! I will not allow myself to geek out on my water like that........so.....do you have any suggested reading on the topic just in case I decide to look into this further? My homebrew OCD is kicking in.

[Mylo]

Palmer has a good article on residual alkalinity in this months Zymergy.


Mylo

[WingStall]

I sent in samples of my tap water, charcoal filtered water, and RO water to Ward Labs for comparison. My RO system seems to be about 75% efficient, but by no means is it putting out near distilled water. Here's the data:

[Stomatopod]

[quote="WingStall"]I sent in samples of my tap water, charcoal filtered water, and RO water to Ward Labs for comparison. My RO system seems to be about 75% efficient, but by no means is it putting out near distilled water. Here's the data:


[/quote

That is pretty high for your tds how old is your filters?