Help with 1 week old 10g nano

[Nixon]

Hey guys, I'm really new to this hobby so I was wondering if i could get any help with signs of an unhealthy tank as well as common pests or things I should look out for. Here are somet things that concerned me but I'm not even sure if I should be worried. If you guys could ID these things and let me know if they're good/bad/ok and if they're bad, what I could get to help it.

I'm currently running a 10g with a rio nano skimmer, maxijet900 powerhead, 50W heater, about 15-20 lbs of live rock, 2 hitch hiker snails (no idea what kind), 2 small starfish (also hitchikers off the LR) and a mystery hermit crab. I also have these little shrimp looking things (very small maybe 2-3mm in lengh some red some clear) that I couldn't get pics of but here are some pics of the others.


Crabby


Starfish



Wierd clump of sand or something with sand stuck on it...


What are those yellow tubes with the 2 "anntenas"?

I really appreciate the help guys and gals!

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Nixon