Hey i got my discus awhile back maybe 5-6 months ago. when i bought him at the LPS with another discus 2 in total. one was torqiouse color and the other was a melon orange. They both were doing fine with my other 5 discus. They are about 4-5 inches long but the torquoise is not eating has not been eating for months maybe 2 or more. He was nice and fat now he is super skinny. he has lost alot of color and became reallly pale he wont eat he stays in one spot all the time. everyone else is fine but he hasnt been eating for months i treated with melafix, salt, methyline blue, high temp at 89 but still nothing. any help? i got him in a 60 gallon tank with 6 other discus and a teacup stingray, i also got 4 amazon swords and 3 anubis plants. 50% water change every 3-4 days.