I Have A Murderer

[ADR]

I did have 7 neon tetras but a red + blue fighter as best described has killed them should i keep it in the tank with my mollies?

 

[catxx]

if it's a fish killer, best to keep it alone. he'll probably still have a go at larger fish, one of my bettas, boo, is the same, he took chunks out of corys he used to be with, even though they were bigger than him!
get him his own little tank, 2.5 gallon's are cheap, or if you want to splash out get a 5 gallon for him.