So I got this driftwood, it still floats so I tied it to a rock with rubber band. Now what concerns me is that the driftwood might float or maybe displaced because of bulldozing ivory snails (the driftwood can be easly moved by my finger) and some unobservable force of water in the tank .. This could potentially free the wood, allowing it to float to the surface and worst, the rock that is tied with it will fall and could roll down and break the glass. I have this problem before when I first kept an aquarium.. It break my aquarium glass and its very upsetting. . Any ideas guys on how to fix this problem ?