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

[bashcraft]

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:


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

Depending on the GPD rating of his membrane, the tds reading could be normal. I've seen 100+ GPD membranes rated at 75%. My 50 GPD is rated at 95% though.

But 507 TDS for unfiltered tap water seems awfully high. My wellwater is ~250.

[Stomatopod]

it's all about rejection rate. I have 1100+ tds at the tap. I have to use a 99% rejection rated membrane but I usually get 0-5 tds.

[WingStall]

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

I took those samples when the RO system was less than one week old.

[BrewTa2]

You might have a leak around an o-ring on the membrane.

Click Here to go to a listing of conductivity meters on eBay. I like these inline meters instead of the hand held ones. Very easy and quick to check. They're sold as TDS meters, but they aren't, they just measure the ability of the water to conduct electricity which is a good enough indicator of how well the system is working.

[SacoDeToro]

I have a GE RO system and I've been happy with the results. I have a few water treatment schemes that I used depending on the style or how I want the final product to taste. While I believe firmly that water chemistry is key to the best beers, I've found that things are fine as long as your target ions are within a given range (+/- 25ppm). So for brewing purposes, my RO system is just fine.

I'm not sure how much of a true indicator this is, but StarSan tends to force ion precipitate pretty quickly. If your RO/StarSan solution is clear after a few weeks, I'd wager a guess that your system is working well enough for brewing purposes.

[boobookittyfuk]

You might have a leak around an o-ring on the membrane.

Click Here to go to a listing of conductivity meters on eBay. I like these inline meters instead of the hand held ones. Very easy and quick to check. They're sold as TDS meters, but they aren't, they just measure the ability of the water to conduct electricity which is a good enough indicator of how well the system is working.

conductivity meters measure semens!

[DannyW]

conductivity meters measure semens!

Refractometers measure urine! (at least at our local vet clinic they do)

[SacoDeToro]

conductivity meters measure semens!

Refractometers measure urine! (at least at our local vet clinic they do)

...and on that note... one of my college roommates worked at a Vet's office in high school and said they used a dental water pick to douche cats.