Not sure what this is?

[Ffelrod]

New 1st tank. Tank is 5 months old. Have 2 corals and a CUC (5 Nassarius, 5 Troches, 5 blue leg hermits, 1 Scarlett hermit, and 1 electric blue hermit. Have Chaeto and Pods. Is this one of the snails? Weird looking!!

 

[lapin]

looks like snail with stuff growing on them

 

[Ffelrod]

0 Phosphates / 0 Nitrates. Cheato is growing like gang busters.

 

[fishguy242]

is it sponge?

 

[Ffelrod]

Ok. Couldn’t stand it any more. Fished it out. It was a crab shell with some algae on it. No crab inside. Not sure if it died or moved on to another shell. Weird. Loving this hobby!!