aquarium fish help

[fishguy228]

so about two weeks a go i got ahujeta pike and i put him in my 10G hospital tank for abouy a week while and he was eating then i moved him to my 55G and then he ate my danio but the feeder guppies i give him are 1/2" and he`s 4 1/2" is he not seeing them?

and today i got a cuvier bichir
but about two hours after i put him in my hospital tank he has red around his mouth? what is happening?