Unknown hitchhiker, ID please

[yoki32]

Hi guys,

I've been cycling my tank for over 4 weeks now and I started noticing some white droppings here and there on my sand and live rocks. I've been trying to track down what it is without any success. I'm new to the hobby so I have no clue whatever is living in my tank right now. I was planning on getting some inverts soon but I don't want casualties if I got a predator in my tank.

I've also woke up at night to see if i could catch it in action but without any success. I used the red light app on my cell phone to illuminate the tank in red. I don't hear any sounds as well so hopefully I have no shrimp in there.

I'm attaching 3 pictures of the droppings. Hopefully someone can assist me in identifying this mysterious creature living in my tank.

 

[SEAMONSTER]

Hi...those are small worms that live in the sand. Totally harmless! They are actually beneficial because they eat detritus.

 

[A1t2o]

I think that what you see in the sand is just a slime trail that the sand is sticking to and looks like droppings. What left the trail there? Hard to tell, but it could be a snail or a worm or even just bacteria. The second pic in the rocks looks like a shell of a tube worm that could (should) be empty now. Feather dusters are a type of tube worm.

Most likely there is either nothing there, or at least nothing harmful. So if your parameters are good, feel free to add livestock slowly.