Blue linkia
 

I have a 110g with 100-150lbs of l.r.
I have had it up for over a year.

I need to know if I can have a blue linkia?

What exactly do they eat?

You could keep any starfish. Linkias eat algae, so if you dont have algae in your tank you might want to buy some.

No one knows what [i]Linckia[/i] eat. The best guess is that it's some component of the organic film that forms on solid surfaces. The size and age of your tank are pretty much the bare minimum for this species, so long term success is possible, but iffy assuming you start with a healthy specimen (which can be the hardest part). See if the LFS will hold one for you for at least 2 weeks, a month would be better. At the end of that time if any part of it looks mushy, white, or sunken, don't buy it. If it still looks plump and free of wounds then it's probably ok to buy. Be sure to drip acclimate it over a few hours though.