First off I don’t know why live aquaria puts the max size at 1 foot for a sand sifting star I’ve watched many videos and seen many sand sifting stars in aquariums through local fish stores I’ve never seen one anywhere near that I think the max size for a sand sifting stars probably around 3 to 4 inches also the link that you put on live aquaria that’s the exact same one I have it looks the exact same right now I don’t know where he is he’s somewhere in the sand but I assume he’s doing pretty good because when I put him and that tiger conch that I have they both clean the sand like crazy my sand is perfectly white now and I had a full on diatom bloom.
Ok great keep us posted how it acting here if you dont mind,like if you see it eat algae etc as i think there real cool critters indeed