Well....
10 gallons isnt a healty situation, but thats not the real problem. Be aware the the blue linkia starfish is the most delicate of all. It shouldnt be added unless your tank is at least 6 months old and must be drip-acclimated for a full 24 hours. If you properly acclimate it, it may survive, but the correct answer is that 10 gallons is too small for 2. What other fish are in there?
ps - be sure its a sand sifter because if its a choc. chip star it will eat your linkia.
I have 2 clowns, a rusty angel, a shrimp, hermits, snails, and quite a bit of live rock for a 10 gallon tank. I was thinking of adding a couple of cardinals. Could I add a bottom feeder as well, like a blennie