White Sand Starfish

[ILIKECOUGARS]

The sand sifting star will eat everything good in the sandbed and once the food starts to run low/out it will start to loose it arms and slowly die.

[janalta]

I've heard the same thing about sand sifting stars...but, my daughter brought one home because it was cool...and it's been thriving in my 55 gal tank for almost a year now.
My sandbed is clean but certainly not picked barren....lots of worm tunnels, etc.