obviously someone who knew about this would post more details than that.
I really get tired of one liner posts that condemn the work people do here without any trace of backup information. simply a stated opinion of opposition.
the frame work he is doing should hold the structure quite nicely and this is a hex tank so the normal dinetions for thickness on rectangular tanks don't apply as none of the panels will be more than 24" wide.
thnx yogurt, the glass calculater I have says 6mm can be used up to 24 x 24. My viewing areas will be 17.25 wide and 20 tall. The math says it'll work.