Brown cylinder shaped brown clumps

[Camões1689]

New to reefing, freshly cycled 50 gallon tank, 2 clowns, 1 blenny, 1 YWG a few inverts.

This afternoon I've noticed these formations speckled in my sandbed. Do you know what they are? Should I be worried and do something?

 

[blaxsun]

Fish poop?

 

[Camões1689]

Can it be this big? May well be I've been overfeeding ever so slightly I think