Air bubbles?

[ClowninAround386]

I'm not sure if it is sand particles or small air bubbles circulating through my tank. I am not sure if this is normal for salt water tanks, if anyone could help or tell me what this is that would be greatly appreciated! (I am new to salt water tanks) This is a 13.5 gallon tank with ~7 lbs of live rock and I have 2 clownfish and an anenome.

 

[Meccaman96]

Does your protein skimmer have a guard over it that reduces the bubbles from the output?

 

[ClowninAround386]

Yes, the bubbles or sand don't seem to be coming from my protein skimmer.

 

[Bunnee911]

Is your skimmer new?