The bristleworm is fine, leave it.

The crab could be a problem. I'd try to get a picture of it. Does it have red
eyes? Would you describe it as muscular? I had one that for some reason
reminds me of a gorilla. LOL

Try to break up the clumps. I get them as well. It could be related to excess
food/waste, or even some type of sponge growing within the pieces.

Marc


TW wrote:

My reef has a crushed coral substrate. It is now approx 31/2 years old.
Recently I have found several new creatures living in my tank that I did
not add. One night I spied a large 6" bristle worm coming out of a hole
in my LR. Then I saw a freshly excavated hole at the base of the LR and
in it is a crab. It is about the size of a grape. It is shaped like a
hand with the finger tips touching. Each leg is tapered from a fine
point up to a somewhat roundish leg. I have never seen it outside its
hole so I believe it is nocturnal. I am now seeing small clumps of
subtrate appearing. For lack of a better description it looks like
clumps in a cats litter box. My subtrate is otherwise loose. I have no
idea what could be creating these clumps in my tank. I wonder what else
is living in my tank

Any ideas?

Todd

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