Koi Forum • Which Glass for pond window? : Your Pond Build

I am just starting to build my first koi pond, and would like to put in a window, but i dont know which glass to use. I assume it will have to be toughened,? Laminated ? and where would i get it from? Its realy inspiring to browse through this forum,there’s a wealth of knowledge and experience out there. I’m starting to compile a pictorial history of the build,and when i work out how to use this forum i will put them in! cheers for listening ,Tim.