Thanks for the article Paul!!!! I was afraid that the sandstone would not work...I'll have to look around and see what else I can find. If nothing else there are several lawn and garden centers around with rock at decent prices.
The salt draws out impurities. At least that is why you use it when soaking/boiling driftwood...I assume it is the same purpose with the rock.
I got my sand today...went to True Value and picked up a 50lb bag of pool filter sand, OMG..they actually had fish, mice, birds, lizards and hermit crabs there!!! The ones that crawl on dry land, not the SW ones...even had a SW supply section never seen a True Value with all that!