RO/DI

[Brad Gardner]

All I am saying when my meter says 0 uS/m, I will use this for top-offs and water changes and feel confident that I using pure to ultapure water. Now weather that is really .2, .3, .4, .5, ....I don't give a S%$^. For reef purposes a 0 uS/m is fine. I am using uS/m instead of ppm at the suggestion of Randy Holmes who does not care for the ppm measurment. I think he said it is at best an approxiamation. Maybe he can chime in.

 

[O P Ing]

hi.
Take it easy there :wink:
There is a paper by T. S. Light presented during the ACS meeting back in 1995 titled "The Conductivity of Low Concentrateion of CO2 Dissolved in Ultrapure Water from 0 to 100 oC"

I feel that the following statement is interesting:

However, exposure of ultra pure water to air increases the water conductivity to ~0.8-1.5 uS/cm, depending on the actual atmospheric CO2 concentration

The authors can not get any water more than 18.18megaOhm-cm (~0.05uS/cm) with an elaborate setup.

 

[Brad Gardner]

Hmmm, that tells me that I should see a reading of at least 1 uS/cm. Right? How long does the water have to be exposed before this increase happens?

 

[O P Ing]

hi.
I found the pdf link by google. This is:
http://www.thorntoninc.com/pdf_files/te ... nd_CO2.pdf

Thronton Associates is one of the leading companies that deal with ultrapure water. Their conductivity meter can measure down to 1pS/cm resolution. I doubt that any of us need anything like this. As you said,

...feel confident that I using pure to ultapure water. Now weather(sic) that is really .2, .3, .4, .5, ....I don't give a S%$^.

 

[wombat1]

Here's some scientific facts for you:
1. My water reads less than 1 on a TDS meter. (yours aint close)
2. Equivilant stage systems, Spectrapure produces better water than Kent.
3. My water is better for a reef tank than yours.
Those are the facts!

...shizz fool, you don't even know!! My RO/DI has 0 TDS and platinum casing, and my TDS meter is 24K gold with a diamond as the on/off switch!! Bling bling on the rizneal!!...

 

[jasonrog]

The company said they will build what I want. My question is what exactly do I want? I would like to use this for my reef and for drinking. Thanks
Jason

 

[O P Ing]

hi.
See the suggestions on page 2 of this thread. The first suggestion is typically what people use in this hobby. Add a bladder tank for holding the RO, and tee-off into drinking and tank water. For drinking, use a carbon filter between the bladder and the faucet. For tank water, either go straight, or add one or two stages of DI after the bladder.