Tomb- I use reagent grade water which is very expensive to buy at retail. I buy it in bulk. For a while, I was buying it from OpticsPlanet online, but it was more expensive each time I ordered it. A week or so ago, I checked their site, and it appears that they no longer carry it. I tracked down the supplier of the water, Fisher Scientific, which sells it under the Thermo brand. The price, with shipping, was about 2/3’s the cost of buying it from Optics. I use it for my KL, as a rinse when cleaning records on my Monks, and to make up cleaning fluids from concentrates like the Hannl, which is not sold in un-concentrated form here in the States. As to benefits, it is costly, but peace of mind- I don’t exactly know what processes some distilled, R/O, DI and other ’purified’ waters go though, particularly those sold in groceries or large retail outlets, the ’lab’ stuff has to meet certain standards, and goes through multiple purification steps. It is probably overkill, but since I usually do one thorough cleaning of a record and that’s it--for posterity--I want some assurance I’m leaving no residue on the vinyl surface. There are different grades of ’lab’ water, and a few sites that explain the processes to meet the various grades. To me, it is a relatively small cost given the sizable investment I have in records. To others, it may be a waste of money.
In my discussions with the preservation specialists at the LOC, they suggested DI water, which is not terribly expensive and meets the objective of not leaving mineral residue on the record. That interview is posted online.