Oscar fish dying
hi, I have done lots of reading and watched lots of videos but i am confused. 5 days ago my oscar fish was not swimming as usual. he had some white marks on his body, i put him on another tank, he got worse i bought ich medication and didnt fix him. I want to know is there any other dieses that is white spots on the body of the fish like ich, to my understanding when fish has ich it will not slow down their swimming skills. but my oscar is breathing heavy and lying to his side. oxygen is full and i already done a 50% water change. added anti chlorine and sault. in my big tank my tiger barb looks like abit of white marks just started on his body but he swims ok. please let me know what i got to do .