I emailed an engineer at a glass company and asked him about glass for my tank. He didn't give me any calculators or details, but responded to my planned dimensions. This is what he said:
Hi Alex,
I refer to your enquiry recently and the details provided.
Please find attached the glass recommendation for three individual windows and the some typical glazing details for your information.
I would prefer using laminated glass for a large aquarium in lieu of using monolithic glass in order to minimise damage and injury in the event of glass breakage.
Hope this is of assistance
GLASS RECOMMENDATION
(Glass design to AS1288-2006)
1) Design Assumptions
Water level: 200mm above top edge of window
Allowable deflection in support framing: span over 1000
Opening size: 570H x 2443W / 390H x 2443W / 320H x 2443W
Support conditions of panel: supported on all sides
2) Glass Recommendation
Nominal Glass Thickness: 21.52mm
Glass Make-up: 2 by 10mm heat strengthened glass laminated with 1.52mm PVB
interlayer
Notes:
1 The above recommendation is for information purposes only and not intended for use
by members of the public. Should be relied upon by experienced members of the glass
and construction industry as general information only and under no circumstances
should they be regarded as a substitute for professional advice from competent and
skilled advisors on particular applications of any product.
2 Always avoid hard, sharp objects coming into contact with the glass wall.
3 Laminated glass products must be glazed to protect the interlayer from direct exposure
to the elements and the pool water.
4 Viridian will not provide design / compliance certificates for the recommendation.
He also sent me a document on pool window glazing but I can't copy it. It basically says:
Glaze from the inside (we know that)
The frame MUST be rigid (move no more than 1/600th of the span)
The overlap must be between 1.25-1.5 times the thickness of the glass
The shops have closed for the weekend so I can't get quotes on laminated glass.