Snorkeler's Cube

Is the mat purple? I can't really tell much from the pic. Did you move them or work around them? If they were touched they will go in. I have some rocks with GSP on it and if you touch, work around and or move them mine will sometimes go in for a few day. I've heard of the polyps not coming out for a week and a half. Probably matters how much ya piss them off. ;-p. I wouldn't worry yet, they will probably come out soon. ;-)

Also, the polyps all turned brown on only one of the rooks after I moved it. Had to find it a new location in my tank. It turned green again. I guess it's happy. ;-)

Hat39406, after reading your post I'm thinking maybe it's the crabs walking around them at night, searching for Valonias and green hair algae to eat... poking them here and there to remove a diminute patch of gha... it could be that...

Stars are usually one of the easiest to keep...I would question the water seeing all the algae....post some numbers. Small tanks can change fast.

The mat should be dark purple. If that's the true color, then it's probaly already dead.

Snorkeler, hi. I'm with jonbear. How's the water quality and how often are you doing water changes while the crabs work on the valonias?

There is also a kind of encrusting gorgonian that color.

I have Green Star polyps, with the dark green mat. I also have Neon Green star polyps, with the pale lavender mat like this. My Metallic Green star polyps have a mat colored somewhere between the other two. The Neon Green Star polyps are by far the most temperamental, and will withdraw and stay that way if touched for any reason. If you have threads of GHA sweeping them, they may stay closed for some time. My peppermint shrimp like to clean between the polyps, and at first this was a huge trigger for withdrawing polyps. They have gotten used to this now, unless the shrimp are particularly aggressive.