Hi, I just got this skimmer and been running it on my old tank to break it in before I set up my new Fijicube 32g AIO. It's been 4 days and it's still not producing any skimmate. I have the airline almost fully open (see 2nd pic), and the skimmer is at the correct height with a little less than 1/4 of the grill submerged (see first pic). I've played around with both the height and the air intake but no luck. The bubbles are going about halfway up the tube. I've checked all the equipment and it's all setup correctly. Any ideas?