imported_Aurora40
New member
Interesting you mention a Brita. I did some testing because this got me curious. I first measured the resistance of some regular tap water, and it was about 12K ohms. I then rinsed the same cup out with Brita water, then filled it up from the Brita. The resistance was about 19K ohms. However, it had also been sitting in the pitcher, so some things like chlorine will evaporate out. I emptied the Brita pitcher and filtered some new water, and the resistance went down to about 14K ohms.
It occurs to me that maybe how far apart the electrodes were is playing a difference, and I really didn't make any attempt to be consistent except that I had a tendancy to hold them in the water in a similar fashion each time.
However, there are also many different types of filters, and the Brita is certainly not intended to create water with no dissolved solids, but rather to remove some particular ones that are harmful, as well as odor- and taste-affecting things.
I have some distilled water and I'll try the test on that to see. I believe pure water has a resistance somewhere around 20M ohms (though my little multi-meter only works up to about 200K ohms), and big-time deionizers can get pretty close to that (saw some stuff on the web about deionizers reaching 18M ohms).
BW, that's why I was wondering if those regular Home Depot-type filters were cutting it as far as water spots are concerned. I mean, they are whole-house type things and mainly intended to get out bigger particles, not to make spot-free water.
It occurs to me that maybe how far apart the electrodes were is playing a difference, and I really didn't make any attempt to be consistent except that I had a tendancy to hold them in the water in a similar fashion each time.
However, there are also many different types of filters, and the Brita is certainly not intended to create water with no dissolved solids, but rather to remove some particular ones that are harmful, as well as odor- and taste-affecting things.
I have some distilled water and I'll try the test on that to see. I believe pure water has a resistance somewhere around 20M ohms (though my little multi-meter only works up to about 200K ohms), and big-time deionizers can get pretty close to that (saw some stuff on the web about deionizers reaching 18M ohms).
BW, that's why I was wondering if those regular Home Depot-type filters were cutting it as far as water spots are concerned. I mean, they are whole-house type things and mainly intended to get out bigger particles, not to make spot-free water.