Not sure if Tempering is requires Scott.... I would pay the extra few $ though for 1/2 thick glass... if your a quality oriented and over-build it kinda gal (or guy for Scott). DON'T use acrylic to glass with silicone to save money! if you have to ask why, sell your tank, house and car, and move to a place where you pay people to take care of you.
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END BRACE EURO CORNER
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CENTER BRACE EURO
ALSO SEEN HERE...
http://www.glasscages.com/prodpics/4528_acrylicaqeurobraced.jpg
OR Check out the Acrylic tanks area of... GlassCages.com
Euros are most common on accrilic tanks, and large glass tanks... and DIY tanks. It's very effective... and you can have these cut from "seconds" glass or not so perfect glass to save a bundle... it's gonna get scratched anyway. You dont need to double lap everything either... and on a tank that size I' d go for strips like 2" wide on the long sides and the short sides so... 2 pieces 2"x5'x 3/8" or better... and 2 pieces 2" x 231/2"x 3/8" or better. and then I'd do like a 3" or 3 1/2" center brace. Makes a great place to set rocks or tools while workin in the tank... you will need to install these BEFORE water goes into the tank as you want them installed prior to the panes being under pressure.
At least thats the way I understand it.
Hope that Helps.
And Yes... after it is installed, a nice wood trim could be installed, and finished. I would use a stain or finish that will stand up to the water and lights (if hot) I would proly check out the diy area...for stain recommendations... I am about to build a light hood and I will be inthe same boat to.