29g Biocube sr3 micro bubble issue

[Keeler]

I'm using an SR3 Skimmer in my 29g Biocube. I'm getting a TON of micro bubbles in the display tank. I recently changed the filter out and and cleaned the back area.
The tank has been setup for 5 months with no issues. In the first chamber I'm running a filter, with some rubble rock. In the second I have the skimmer with a protein bag and in the 3rd just a heater and the sponge filter. I've tried adjusting the nozzle on the skimmer and it hasn't helped. If I unplug it, the issue goes away so I know it's the skimmer. It's never had any previous issues though.
Any thoughts?

 

[brian242pa]

Once I heard that u had sculler I immediately new that was problem without u telling me, there may be crack somewhere in it, if possible I would take out an turn in on in a separate container and u cood see the problem with ur eyes