LOL...
Where did pool come from? Read the thread. That was the whole point. Burying a cargo container deep underground with a POOL ON TOP OF IT is asking for trouble. You should at least get an engineer's opinion. Are you digging in Marine clay? That might be one question to consider.
Wait...I changed my mind. Tafbang you are completely correct, my apologies. Please go build your secret deep underground grow room with a pool on top of it. Spend as much time in it as possible. Check back with us in a year.
I'm not saying shipping container as a grow room can't be done. I know it can be done...with some common sense applied. You know, like don't put unbelievably heavy shit on top of it. Like 80 tons of water, or 40 feet of earth.