Dying Anemone help!

[neltel_7]

The past couple days my H. Crispa has not been doing very well. It has detached and fell over. It is still accepting food but is rather small (it was really small, to begin with, but looks extra small) and the tentacles have gotten thin. All my parameters look good and I have good flow and lighting so I don't know what the problem is. Should I take it out? It is only 3-4 inches across when fully open so I'm not sure if it would kill everything in my 100 gallon tank if it did die but I don't really want to take the risk. It's not deteriorating but it doesn't look happy at all.
Would an anemone this size kill everything in my tank if it died?

 

[Hemmdog]

Post parameters and pics.

 

[specwar]

The past couple days my H. Crispa has not been doing very well. It has detached and fell over. It is still accepting food but is rather small (it was really small, to begin with, but looks extra small) and the tentacles have gotten thin. All my parameters look good and I have good flow and lighting so I don't know what the problem is. Should I take it out? It is only 3-4 inches across when fully open so I'm not sure if it would kill everything in my 100 gallon tank if it did die but I don't really want to take the risk. It's not deteriorating but it doesn't look happy at all.
Would an anemone this size kill everything in my tank if it died?

If it was real bad it wouldn't eat and would take on what I call the "raw scallop" look. How long have you had it in the tank? Did you place it or did it find it's own spot?