i used plexiglass (1/8" to be exact) and a but load of silicone and like perpetual98 i can pic it up by the baffles if i need to (but why would i)?the key is all in the silicone bead. my bead looks good on the outside but is FAT on the inside. and with my floss and foam filters between the baffles there is absolutly no room for them to flex or bend. hope this helps as i also have a 20gal sump/fuge (glass) and plastic baffles.