Protein Skimmers for Saltwater Aquariums, Hang On Back Protein Skimmer for Fish Tanks up to 80 Gallons, DC Pinwheel Pump

Distance to remove the cup? I have about 18" available in my cabinet. Is 1" clearance enough to remove the cup to clean.

Would this be to big or over kill for a 40 gal tank?

I’m unable to adjust the skimmer keep water from entering the collection chamber. I have to have the sewage valve open to keep the cup from over flow

What is the depth of water the protein skimmer needs to sit in a sump tank