bubbles from Wave Box

[strittmatter]

There are no mirco bubble coming from my sump and I can see some bubbles coming out of the wave box. I have the wave box summerged to the water line mark on the box. Any idea's why i am getting bubbles out of it?

 

[rvitko]

Check the pump, make sure the sponge is not covering the intake, it should be on the back of the pump, also make sure the solid side of the intake screen faces up.