fresh water flesh eating disease in wild fish

[MFISHERMAN]

I have a 30 gal tank it has one filter for a 90 gallon tank. i have like 4 chubs in it that i caoght out of salt creek i had 3 of them for a month and i caught another one and after a day i noticed his face was deteriating and he died 2 days later with half a head. 2 other fish have it now. How do i stop, cure or get it out of my tank?

Thanks

Mario