When I first got him he was around the size of a nickel and was sold as a “micro pincushion urchin” (it was like 10$ cheaper than the other larger pincushions, so I purchased it.) He’s grown around 4x his original size in the past few months. There has never really been any spine loss! Just 2 on the sandbed once, but I haven’t seen any since. The urchin has an unlimited supply of hair algae to eat, and my water quality is pretty good! Anyways, I’m just wondering if there’s anything I need to look out for, or if there’s anything wrong?