I just got one 12" mbu Puffer , i would like to know it safe to put him with bd stingray or any kind of ray tank ? 


MMMMMMM $1000-2000 bd with a $100 mbu why risk it
if one person said its risky i wouldnt take the gamble
My mbus have only done well in hard alkaline conditions. If BDs can tolerate the same conditions it might work. However, I've also had mbus that were notorious for nipping at anything on the bottom with test bites to check if something was food or not. Not a good thing for BDs if you get a puffer with this trait.