One thing to remember. Non tempered will usually just crack, often just causing a leak.(be it minor or major) If you are lucky,the crack will be in the higher half of the glass which means your tank will only drain to the crack giving you some time to save your stock. With tempered, if it breaks you will definitely end up with all your fish on the floor in one clean swoop.That's guaranteed. If you are worried about safety to your kids, use a thicker piece so you have at least a 3.8 safety factor. Cost is another consideration with the tempering process jacking up the price.
A whole 6 feet? Which would you rather have hit you, a few thousand lbs of water with small glass squares or a few thousand gallons of water with large shards of glass? The debate will go on forever but I will say this, if tempered glass was so easy to break and plate was so much safer then why is it code for so many things to be tempered glass? I think the problem here is to many of you are forgetting how much harder it is to break tempered glass over plate. If you PROPERLY place the tempered glass in whatever setting its going in and the edges are protected then the chance of it breaking compared to plate are significantly less.
