Protein Skimmer Help

[SinkyShippy]

I have a 20 gallon tank with a glass hinge cover. I purchased a few protein skimmers but they don't seem to allow the hinge cover to stay flush with the tank because they're too wide for the space. Does anyone know some protein skimmers that would work in the tiny space or, perhaps, a smaller external protein Skimmer?

 

[Flippers4pups]

To make things easier, I would replace the top with a DIY screen top. Better gas exchange and would allow you to run the skimmer that works for you.