I would second Fixitt's suggestion of using acrylic. It's used for making wet/dry filters and aquariums in the "fish world" all the time by both fish hobbyists and professional companies.
Further FYI - you can bond acrylic with acrylic weld cement. You can get it in clear compounds. It contains solvents that "melt" the acrylic to form strong water tight welded joints (so no need for screws, you almost never see screws used in aquariums or wet/dry filters and pre-filters).
It is also drillable without cracking issues (when done right). However, screw in metal fittings aren't usually used. Much more common are press fittings that use o-rings for sealing at the acrylic wall interface. (they are threaded, but the threads are for a compression/retaining nut that goes on the inside of the wall)
Oh- and for high strength use cell cast acrylic
