I've been watching this thread for a while and I'm a little confused. Is there a problem with conventional aquarium hoods as long as you cover the holes in the back? I'm not sure why everyone is battling over the right plastic to cover an aquarium with. Glass cleans easier and is more resistant to scratches than anything else. The only application tempered glass won't work with (to my knowledge) is in salt water tanks where the UV from coral grow lights won't penetrate the glass to any great degree.
Also, on the issue of glass... If you buy the glass from a shop that does residential and automotive glass, they will not only cut it for you, but professionally (and safely) grind the edges so they are smooth.
If I'm off-base here, somebody let me know, since I am a newbie here and haven't "earned" my stripes so-to-speak.
Have a great day all....