Purchased a purple Firefish a week ago. I put it in my planted tank as a temporary holding tank before it would go in my display. Same day I added an Aptaisia eating filefish to hopefully take care of the infestation of aptaisia. I haven't seen the purple Firefish once since I put it in. I have an acrylic lid over the tank, so it wouldn't jump. I checked around on the floor just in case and no sign. I've never had one of these fish before. Is it common for the to hide or burrow this much to where they're never seen? Or did it probably die?