New tank 300 gallon

[abcha0s]

3/4" inch rimless would be over speced.
5/8" rimless would meet acceptable safety standards.

The major consideration is the height at 20"

I prefer over speced, but you will pay significantly more for the 3/4" and if it's not necessary, why bother?

If your interested in how I designed my 300g, you can read my build. If I had a "do over", I would have gone rimless.

[lastlight]

What's appealing to me about using glass a little thicker than needed is the greater width to all the seams. I'll be doing an inner eurobrace on my next big tank on the bottom...sides would be too ugly. But a 3/4" seam would be very strong I think.