In February I started a new 90 gal tank and started using an aqua c ev-120 skimmer with a pan world 20 w external pump in March. The pump was recommended by the online vender I purchased the skimmer from. After many attempts to get foam I am at a loss. The water level is at the recommended level but still very large bubbles and 1" of skimmate after 2 weeks of operation. I would appreciate any suggestions.