Wow, thank you. I just learned a bunch! Although this is for a mister, I'm actually going to use normal tap primed for my tank water. So this isn't exactly a water stability issue, although it'd be nice if it drank well. The reviews on the below seem to say it does.

Any thoughts on this?

http://www.bulkreefsupply.com/brs-4-...tem-75gpd.html

I'd consider the 5 stage one, but I heard elsewhere that RO/DI water is so pure it can actually erode the mister heads, or something.