Fluval 107 micro bubbles

[DEL 707]

I've noticed for the past week or so that my fluval 107 is constantly spitting out micro bubbles.
I've moved the filter about used the primer to see if I can flush out any trapped air, but it doesn't seem to help.
I clean out my filter every 2 weeks and it's been 9 days since I last opened it up.

Any ideas on what could be causing the micro bubbles?

 

[Peace River]

I'm assuming that you filled the canister up when you serviced it. Have you checked for air leaks?

 

[DEL 707]

Silly, question. How do I go about finding air leaks?