these are the things i used:\
a 50" clamp straight edge bought at home hardware
http://www.homehardware.ca/en/rec/in...tt=clamp+guide
a mastercraft router /dremmel but a bit bigger than a dremmel... some ppl use rotozips or dremmel as well.
i chose the router more so for the flat edge to keep cut straight... side note make sure glass not tempered... i was lucky i didnt check and should have
i used this bit on the router cut like butter. found it at home depot price range 36 to 40 bucks
i used thesame bit to cut the round holes for my drain pipes too worked well cut freehand... just a note dont use too thin of glass i had to rebuild the overflow cause i used 10g tank glass for it and broke it twice... durring the build...
best to cut outdoors and use garden hose to keep bit cool i had mine on mist
go slowly. you can polish the glass again with a dremel if you choose with a light sand paper bit. and i did the down cuts free hand marked on glass with marker
if you go too fast the glass may chip alot but if you cover with black acrilic it wont matter. after you have gone halfway tape the already cut side to help reduce vibrationas well as the glass falling on to opposite sideand cracking the glass. as an extra precaution lay some old rags under it to prevent as well. again things i didnt do but got lucky.
i hope i got it it all for you and this helps if you have more questions please ask and ill try to help.