you have to tie it down to something. Mine was initially tied down to a peice of driftwood and after a couple of weeks i started cutting off the threads. It is now out of control and severly attached. It is growing off the driftwood now and making a mess of my tank. It will pretty much stick to anything after some time and a mechanical attachment. As far as getting it attached to the gravel, just stick part of a clump under the gravel to keep it down. That part will probably die off but not before the exposed parts on the top grab onto the gravel. HTH