could be ill discus

[pikeman]

i have an orange discus that seems to stay in one place some times with one fin in it also is quite thin
but still eats fine .but my others swim everywhere and he doesnt
whats wrong with it

[pikeman]

help :D

[DR.V]

Did you just get the discus recently ?

Whats your water parameter ?

[pikeman]

quite recent
parameters are as follows
ammonia 0
nitrite 0
nitrate 0-5
ph 7.6