In my experience with such tanks, carrying them in the back of pick 'em up trucks, abrasion will kill you sooner than anything. I carry 400 gallon tanks and they seem to be plenty strong and, while I have not measured wall thickness, they are nowhere near 1/2" thick. Secure the tank well, perhaps gasketing the bottom and contact points for abrasion.
Avoid excessive chlorination as chlorine is an oxidizer and will "dry out" the plastic causing it to become brittle with age, and cracking. UV light does the same, but I don't think that's going to be a factor in your situation.
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Wm. F. Buckley, Jr.