Ok i have an opportunity to save an Oscar from a short miserable life in a 10g tank...but iam more of a salty guy(yes i got freshy) what size tank would be appropriate for a single Oscar...and are "cory" cats safe with an oscar??.i do have an empty 55g (atleast for a hospital tank...may have ich since they said it had a white spot...i dont know yet as i have not seen the fish yet)