I wouldnt even consider 1/4" glass for a tank like that.you are going to have a lot of stress points unlike a standard rectangle tank, would suggest at least 3/8" and a bit extra for safety. also im not following how you plan to attach the acrylic base to the glass? Silicone has no weight adhesion to acrylic, and weld on wont work on glass. I dont think making a channel in the acrylic would work, ad it would put a lot of stress on the glass on the outer inset edge by the acrylic groove top. wow that was wordy, hopefull you understand where im talking. A Glass shop should be able to cut the base you want as long as you have it drawn out good for them, where to cut. Would suggest 1/2" for the base Glass. Other than that good luck-Brent
