How about this..The tank is going on the tile floor in the pictures. (which has concrete below it)
I dont think insurance covers fish tanks lol.
Thanks, we only plan on moving it in an emergency.
Buy a 300 gallon rubbermaid stock tank (or two)
In an emergency, put all fish in stock tanks, empty the big tank completely and do what you have to do.
This is insanity.
Also, you can not trust caster ratings.
As an example, I put a 800 lb tool on 4 casters. Each caster was rated over 500 lbs so I thought I was safe.. Well, I moved it a little bit a few times, then one caster blew out on me.
Another issue you will have.. Even if the bolts and casters hold up, now your bottom is not completely supported by the concrete floor. All that weight on the wood will cause it to sag over time and eventually leak.
I am pretty sure you will ignore this warning and do it anyhow, but I felt obligated to warn you.