fish black molly agression?

[Nadine]

I have a black molly that is has always chased and harrased my fancy tail tertra.today it went to far,The moley was dodging and chasing the tetra.The tetra had almost all of his fins gone including the top.We dont have time to go do any drastic changes with large tanks tonight because my husband has a medical appontment in the morning so I went and bought a cheesy cheap 1 gallon tank kit with a cheap undergravel bubller filter thingy.Anyway its a 2 inch molley and he looks like he is going crazy in there.Do you think he will be okay for a day like that.If I put him back in the regular tank he will chase my tetra.The bad thing is I have let it go this far becaues I favore my molly but I cant allow abuse and I dont feel that moving the tetra out of the tank after all its been threw .how long do you think that the molley will last in the 1 gallon.I am going to look around for something else.