Water purifier

[Aquattro]

Basically, if you're going to keep any of the water in the tank after cycling, you'll be better off with filtered. Generally tap water is OK if you're curing rock in a tub or something, but unless this is really stinky rock, I'd fill the tank with RO water and this will be the initial setup. The rock will cure in this water and when the levels are normal, you can start adding things (slowly)