The build quality is ok for the price , 389 + tax (13% in Canada), material similar to Deltec . You can see the bubble starting build up at the same day. I have a Deltec and it took weeks for me to tune it right. It is running with low noise , almost silent.
I dropped the water level 1.5 inch, will see how the result be. Thanks for your suggestion.
One thing I found, may happen to other skimmer. When feeding, the bubble is below the cup, but it recover to original level very quick