I have a 55 display and 15 QT. I tossed in a very small piece of figi branched LR in the QT for my clown to hide in, and I got the same little white "starfish" looking things. My display tank has some of the same branched LR, but no sign of these star-critters.
I'm pretty sure they are not true starfish, and they are not copepods or amphipods. That I am sure of. Do yours look like real small snowflake like creatures, with maybe 6-8 tiny tentacles, and adhear to the glass ??? I have at least as many as you mentioned .. maybe more.
I'm going to try and figure out what they are, and if so I'll let ya know.
Brian