I guess all I need in the container with the rock is a powerhead (no heater/filter etc.)?
And, for the waterchanges, would it be ok to replace the water with used SW from my main tank (ie. after a waterchange in my main tank), as opposed to new SW?
And, for the waterchanges, would it be ok to replace the water with used SW from my main tank (ie. after a waterchange in my main tank), as opposed to new SW?