I agree. T.Crocea and T.Maxima's like to be placed on rock. They will attach to the rock with little thin ligaments, and once attatched, they are hard to remove. If you do not cut the ligaments correctly, and end up pulling the clam off the rock, you will damage the clam and possibly kill it. I suggest placing the clam on a small piece of LR, let it attatch to that. Once it attatches to the little piece of LR, then you can move the small piece of LR to wherever you like, and both you and the clam will be happy.....depending on water flow and light too of course.