So, I had this skimmer for a good while and worked perfectly, producing a lot of skimmate. For a few days now, it's not working properly. The pump is working and the venturi is sending bubbles in the skimmer. The water spins and ascends to the skimmer's neck, but it's not foaming up as it used to. At the top of the reaction chamber, where the bubbles should be many and foamy, it's too wet. There's no foam line anymore, but I remember that when it was working well the top had about 4 Inches of heavy foam. I cleaned the pump, inside and out, I cleaned the elbow and poked the venturi hole where the air inputs hose connects to and nothing. I tried regulating the knob, but it doesn't help. The top is still super wet and not foamy enough. The water isn't too clean, I can see the glass getting dirtier by the minute, so there are enough nutrients in there that the skimmer should be able to pick up if operating as it should. Can you help me through a check list to troubleshoot this issue, please? I should add that the water output is putting out a lot of micro bubbles that make it to the display tank, where before it didn't put any bubbles out this way. Something is not right. I thank you in advance. - Mag.