When do you know if your tank is ready to have a sand sifting starfish? My tank has been running since February, have 15 fish, several types of LPS coral, and a few inverts.
I would personally never add one. They'll deplete a fair bit of microfauna in the sand first, and then starve/die after. It's really not a good creature in a captive system unless it's several hundred gallons.