do you have it up on the rocks or down near the sand. Most crispas prefer to wedge itself either on the sand or between the sand and rock. When I first got my crispa, it didn't stay put until I dug a little hole in the sand next to a group of rock and placed rock around it so the flow didn't push it around. Within a day or so, it attached and hasn't moved yet. I then moved a few of the rocks away that it wasn't attached to (my false percs also rearranged some of the rocks once they started hosting it!!!
