Unsure how they did it, but Down Corning 795 is what I've read.
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1128845
Nice little thread, includes good information, someone on RC who's often a "know it all" (usually right too) being told he's completely off his rocker by someone who does know more about the subject, it's great times
[quote author=Elite link=topic=3677.msg47647#msg47647 date=1214794668]
Is it my eyes or the black board on the bottom doesn't cover the whole bottom?
[/quote]
Yeah it looks like there is an 1/8" gap on the front and rear of the tank. Like it is the exact width of the bottom piece of glass and not the front and rear panels
Everything is fine they cut the last inch crooked at the end, hey it's holding water, I'm just glad someone fixed it. 97 more days of water testing I can put it in my new house, please just be happy for me I can't take more tank stress. ohm.......ohm.......ohm, good times.
I am determined to make this a world class reef tank, The aquascaping is going to look something like this, so it will look more realistic. This is the reflectors I have (Luminarc III's) I will build a rack just like this one too, should be a fun tank to put together.