I didn't read every page, but I just wanted to go off the "dry season/monsoon season" argument.
The Amazon goes through a dry period too, but would you use that excuse (when the fish are living in dirty little pools) to put THIS into a bowl?
Not even considering that a piranha wouldn't FIT into a bowl, but still. They go through similar conditions, and yet people still know that you can't comfortably keep a fish like this in a jar.
So, why would you put this fish in something smaller than the container your soda comes in?
I can buy bottles of water bigger than some of the "tanks" they sell.