The clam was attached to the plug when I bought it so I don't want to try and remove it. I run barebottom so I was planning on putting all my clams on some sort of plug or small rock so they don't attach to the glass anyway. I don't think there are any issues doing it that way? There is plenty of light at the bottom of the tank, I'm running a Kessil A360EW and the tank is shallow at only 12" so there is plenty of light just about anywhere on the bottom.