So sad ytd aftn to see my 4ft tank almost going to crack due to the water pressure too strong from inside, the back glass bended outward by 8mm, from the below photo u can c the centre bracing glass dropped off from the back glass, it was so terrifying, luck my glass thickness is 12mm, just imagine if is 8 or 10mm, what will happen? So, if ur tank is about 2.5 or even 3ft height, pls remember to use 12 to 15mm thickness of glass, and must be euro bracing all rounded with centre glass, ur centre glass must be wide enough to catch the back n front glass, also, remember to request for MORE BLACK SILICON (Good quality type) when u want to build ur new tank.