I want to drill two holes in the upper center of the back wall on my 75 to drain down to the fuge and sump. I'm pretty handy but have never worked with acrylic and want to make my own internal overflow box. Something like what gl*******s.com makes. But I don't want to spend $100 on something that I could do myself and probably only requires $15 in materials. I know I want to use black arylic, I'm guessing bent with heat as opposed to glueing the four sides together would be better? I'm not concearned with making teeth, I would rather use black eggcrate to serve as a strainer to keep critters out. I'm thinking (two) 1 1/2" bulkheads with 90's pointed upwards inside the overflow box, and "T"s on the outside, one end pointing up for a vent, the other pointed down to drain would work? Does any of this sound correct? Also, if any of you guys have made your own internal overflow box could you please post some pics for me??? Thanks!