I just got this Harlequin the other day. 1st time owner. My tank was over run with asternias. Any advice on keeping them happy (other than an abundance of starfish). Any problems you've encountered with them?
They have always been easy to keep until the starfish run out. They go about their business out of sight for months if the tank is overrun and large enough.
Asterinas aren't enough to sustain them forever, they burn through their population really quick and you'll either have to supplement it with other whole sized starfish twice a month typically or forward them to someone else.