tempered laminated glass thickness for pond viewing window

[giar]

Sup folks..

I am debating whether to get 12mm+12mm or 15mm+15mm tempered laminated glass for my arapaima cage.

Im building a pond with viewing window.

Tank/pond dimensions
600cm L x 350cm W x 100cm H

The pressure at the very bottom of the tank is 16.9psi.. however i cant find any references of tempered laminated glass thickness vs pressure it can whitstand.

Please help

 

[giar]

The 12mm+12mm price is around 180 USD/m2

The 15mm+15mm price is around 490 USD/m2

The price difference is significant

I am getting 6m2 of that glass for the viewing window.. but which one do i really need lol


Thx