Thanks aerialedge, I enjoyed your movie also. To answer your question, I`m not sure about the special grade German silicone....sounds like a marketing ploy I asked a local tank builder that works out of a LFS here for tips before making this tank. He said normal aquarium safe 100% silicone is fine no matter what the brand. He makes hundreds of tanks a year. I watched him cut glass for about 30 mins....think I creeped him out a bit by just analyzing his techniques. Of course he could be lying in hopes that my tank will bust and I'll have to end up buying one from him....hmmmm. Naw he seemed legit Think no matter what the silicone is, if you go over a certain length or height you may want to consider adding braces of some kind. The measurments are listed in the links provided in the YouTube descripion....can't recall them off hand. If you don't want braces on a bigger rimless tank then it'll require thicker glass and near perfect engineering. hth.