I've used various pieces of driftwood throughout the years that I had collected in nature. I have a couple of pieces which I'd used in tanks years and years ago, then took out and they in turn dried out so now they float. I drilled them and screwed terra plant bases onto them for weight so I could have them in the tanks. How long before they are water logged and able to just sit at the bottom on their own? Also is there any danger in having a few pieces of floating driftwood just floating in the tank and getting moved by the filter current?