Used this kit from HD. Mine is only a 20 long so the size of hole i needed for my bulkhead is much smaller than most large tanks.
Works well. The "water delivery system" is pretty nice and I think the adhesive actually makes the glass a bit stronger while drilling.
The second image is basically how its going to be set up. Im going to make a 29 gallon sump underneath. I need to find some specs. I want to make the sump bigger than the water volume just in case the pump fails and the overflow keeps going. If anyone has a good spec out for a sump Id appreciate it. I was even thinking of using some 1/4" plexi and the left over rim to my first attempt at drilling to build my own sump from scratch. I think it would be a cool project and i still have all the jbweld and such for it.
looking to turn this into primarily a reef invert tank. Maybe some easy small fish like damsels (only damsels though) or maybe put in a mandarin and build a feeder for it (them). Im only going to keep minimal rock in the tank and leave the rest below. God forbid I end up with another outbreak of that briopsys algea. Id rather leave it all in the refugium and not look at it. Clean 2 or 3 rocks every few weeks than like 12.
Dummy me though, left my rocks out all winter/spring/summer after the tank crashed so theyre all dead and has who knows what on them. They were in a sealed plastic bin but I figure a good rinse and maybe put them on a foil pan in the grill for a bit to kill any harmful cirtter or bacteria. Then Ill have to reseed everything.