I'm planning a new tank, and I'm trying to decide between 5'x3'x2' (LxWxH) or 6'x30"x24", both work out at almost exactly the same volume. I've got quotes from a couple of reputible tank builders [won't name names], one who says both sizes will be fine in 10mm glass (and said he could go up to 6'x3'x2' in 100mm, just) and the other who has said all three sizes will need to be made from 12mm.
I've had a bit of a play around with the glass thickness calculator, but I'm not sure what to make of the results. I've seen plenty of 6'x2'x2' tanks made out of 10mm glass, and my old 5'x2'x2' was made from 10mm, but according to this they're unsafe.
Could someone a bit more clued up shed some light on it? I know its logical to go for the 12mm, better safe than sorry etc, but its going to mean a big increase in price and weight, so I don't want to waste money on 12mm if 10mm is enough.