I go back a long, long time time ago. Tried a lot. Did some collecting and even kept a Banded Cat Shark and pet Octopus. I kept Anemones and tube worms but never kept corals. Seems everyone I knew had their tanks crash after a couple of years. Stayed in the hobby breeding fresh water fish and active in clubs. Now I found You Tube. People were keeping coral alive in a jar. Did not believe it but I had to try. Goes back a couple of years but I picked up a vase at Walmart and purchased some live rock and corals. Saw them grow and great but then algae. Covered and smothered everything. I tried everything to get rid of the algae and almost gave up but then I found a pincushion urchin. Snails did not work, shrimp didn't and neither did the crabs but the urchin cleaned everything down to the white coral skeletons. The problem is he is like a bull in a china shop and moves everything around and turns things upside down and even stabbed my Kenya tree. Sadly I have to get rid of him. I don't want to flush him and kill him but can't replace any coral until he is gone. Question- What does everyone do when they have to get rid of an invertebrate?