Finding ultra-pure water locally...

Guys, I have had a home RO filter for 30 years. It get replaced once a year. At the end of the year the water has about 300 non-water parts per million. After it is replaced this is 3 per million. Our chemistry department has a much higher quality RO device. They certainly were not impressed with my home results but did not mention what theirs yielded.

Hdm, assuming that you meant to add distillation to reagent water, I cannot imagine that adding salt back in as a softener would be used.

Cello, my tests also show that ultra pure water is superior at least as a final rinse to RO water.

Hdm, the reason we have a RO device is that the sodium content of our water is quite high, but it could not be softer or we would never get soap off our bodies. I would just imagine that even a home RO machine would easily get lime or other minerals out of the water as easily as it would get salts out.

Let see to really do this right we would need to have a broad range of purity as well as price. We would need to do a broad sampling of records to be cleaned and then rinsed with our rinse water. From my experience with Walker's water and both distilled water bought at the grocery store and RO water from my unit where I heard a cleaner record with the Walker, we might well expect a strong relationship between price and purity, but would we see a strong relationship between purity and cleanliness of records and their sound? Or would waters with relatively high to high purity sound the same down to some point where the sound went bad. The lowest purity before the sound went bad would be the best buy. Do we know if it is a linear and smooth relationship or a step relationship where there is a sudden jump as purity increases? I don't think so.

Markd51 and Crem1, as we really don't know what the benefits of purity are, I do think we have to go by what we personally judge to be pure enough. I have found, as I noted, that Walker's water sounds better as a final rinse than either store bought distilled water, which should be a pure as the steam that it comes from, and reverse osmosis water. Given what I use I will continue with Walker's water. I do wish some scientist would evaluate the benefits of greater purity for various purposes.

As I said, do what you need to do, as there is no real information on which to judge the needed purity of water you need. I probably would have continued to use RO water as I had been using had I not tried the Walker Prelude system.