Help with 1 week old 10g nano

[Nixon]

i'm not sure if this is normal, but i just got my light today and when i have it on, i can see a bunch of little particles floating around in the water. is this normal? it makes my water look constantly dirty almost. i have it as an "open top" tank. is that what could be contributing to this? if anybody has any ideas, please let me know thanks!

i'm running:
- about 15-20lbs of live rock that was in an established tank before i got it.

- rio nano skimmer
- maxijet 400 powerhead
- current USA 80W 50/50 power compact.

p.s.
tank is now about 2 1/2 weeks old.