How thick of glass

[Jake1]

I want to make a glass tank and would like to know what thickness of glass I should get. It's going to be a 12 inch or 18 inch cube. The 12 inch is around 7.5 gal and the 18 inch is around 25 gal.

 

[TrueReef]

the 12" i would say 1/4" thick glass and on the 18" i'd use 3/8"

 

[Jake1]

Thanks.