Hello, My name is James and I have recently been given a 8 yr old Discus fish, with a 35 gallon tank , filter and heater. In the last few days the fish has been being strange and is facing vertically. like looking straight up, if the fish is sick i would like to know and correct w/e is wrong, but I'm hoping someone has had similar issues and can help me. im not sure if it is not enough heat , hole in the head, or PH levels, the fish is blue /w black strips vertically down its side , 6 or 7 in long X 4 or 5 in tall. Please help any suggestions would be greatly appreciated. 
/www.fishforums.net/index.php?showtopic=2330