My royal gramma died sometime in the past 24hrs. I saw it alive once yesterday, but since then it been in a very small hole in the rock work, not its usual cave, and definitely not moving. For the past week it has had some kind tail infection, so it isn't a surprise death, but we couldn't catch it to QT either. In order to remove the fish from the tank we'd have to break apart the rock work which we really don't want to do. It's such a small fish that we're wondering if it's ok to let it decompose there. What are the risks, and how could we mitigate them without harming other fish and corals? 20g cube tank, two other fish, and some lps corals.