Record cleaner

I don't kmow much but I do know a little about water treatment. I do it for a living, working for "Imagination at Work". Distilled would be preferred over demineralized or deionized or simple filter purified water. Assuming receiving vessels, transfer lines, along with any final storage containers en route to you are "clean"...this will have the lowest mineral content. Distillation basically evaporates water leaving behind all dissolved solids (mineral species) and suspended solids (particulates). Then the water as steam or vapor is condensed back to liquid form. Multi stage distillation improves the quality of product water (same applies to good vodka and product ethanol). Deionization - particularly when done with resins - can result in a water that is highly contaminated with microorganisms. Resin beds do tend to become microbiologically fouled over time. There are more exotic demineralization and filtration processes that can provide a high quality/reduced mineral content water (e.g., RO) - but from an accessibility/reliability/purity point of view - distilled to me is the way to go.

Ketchup - I'd be very interested in knowing what specific issues were raised relative to use of distilled water for LP cleaning. I can't really see any - it's as pure as you can get but it's not like I'm infallible on this particular application. Storage and handling are the wild cards - but these caveats would apply to water produced by any purification/demineralization process.

Ghosthouse,
If accessibility and cost weren't a factor, what would you use?

If you're on the internet, have a mailing address and you can afford $159.00 there's the KAB EV-1. It has made a big improvement in my vinyl playback. Otherwise you can build one.

Kethchup - sorry if that comment sort of confused things...My point was looking at how easily and consistently you can find distilled water + it's great purity (at least as originally produced) - I'd still go with it over all the other options. I don't think spending more will get you anything better EXCEPT, POSSIBLY...a USP "grade" of distilled or electronics grade distilled. If I remember correctly, USP is like phamaceutical or hospital grade stuff...so I think the supply chain might be a little better controlled than just getting distilled at the grocery store. I haven't looked for it myself but I expect you could get USP distilled at a pharmacy. Electronics grade - what I mean by this is the semi-conductor industry has some very tight specs on water quality...ultra low conductivity so extremly low dissolved mineral content. I don't know the details of the water purification systems they install (whether they use distillation or some combination of methods; maybe just multi-stage RO) but these systems do represent major capital investments. Probably not a practical source for hobbyists.

Listen2tubes- I am interested in your experience with the EV-1. Am planning to get one in the near future.
Sounds like it is working for you.