Originally Posted by NeoCatsy
Yes, its a reef light. Its a florescent green mushroom.
I have no idea what a reef light is.
Mushrooms can move, but they certainly don't do it quickly. They usually pull the foot along until it rips from the rock. If they've moved up and under rocks they may not have been properly attached.
You can use the netting that onions come in and some rubber bands to secure them to some rocks and then leave them in a very low current area for about 2 to 6 weeks to allow them time to attach themselves to the rock.