corals with soft polyps extention may retract when walked on
The star looks small, it was just a thought, I have shrimp which walks on some of my corals and they retract which makes sense.....
If your getting your water tested at LFS be careful, some, but not all, do not do very good testing....To be honest.....the only person who reports on my water is me....
Yup....starfish can walk over anything.....bigger ones....say hand size...can open clams!