Big bubbles in Skimmer

[Sal Crescitelli]

I have a lifereefVS3-24 skimmer with a Mag9 pump but all I'm getting is big bubbles. I have the gate valve closed past !/2 way down but just big bubbles. What am I doing wrong??

 

[drparker]

Are you just testing with freshwater? you can't get good bubbles with freshwater.

 

[Sal Crescitelli]

That must be it then ..thanks