I asked about monsterfishdude because BCaquaria site he uses the handle jling , He was on this site not long ago got an aro in an uncycled tank and had to sell it told me he was going to start over a few weeks later. Also noticed this other Jling or ("monsterfisdude" on this site) was also looking for Tahitian moon sand for his aro on bcaquaria, and oddly enough you also have a post here at the same time titled ...
"s tahitian moon sand safe for arowana? "
both of you were asking about Asian aro's and PH/KH at the same time too...
All much just be a huge coincidence ... Though for a second there you might be the same guy trying to hide that he's putting all these fish into a 160g tank that isn't cycled again and didn't want to hear all the criticism he would get.
Glad that's not the case here though...
youtube is a horrible place to go for examples, Yes i'm sure about the puffer do a bit of research and you'll find the same.
You can put anything you want into a tank for a short period of time, stress of a new home and often incorrect care keeps them more docile and lethargic but it's stress holding it back, when they settle in and clam down they rip each other apart but nobody brags about that part on youtube they just show off the bran new setup with new additions and you never see the end result of dead fish!
How big is your tank ?? Did you know how big these fish get ? Too start i would separate that Mbu wont be long before he starts nipping and then snacking on tank mates!