Do you mean that the fins are laid back on their sides and not waving? That is what we call "clamped fins" and it means that the fish is not well. The problem at this point is trying to find out why...are there any other signs or symptoms that are different?
Also what size is your tank?
How long have you had it up and running?
Did you cycle the tank through the Nitrogen Cycle before adding the fish?
Can you send us the test results on Ammonia, Nitrites, and Nitrates?
If the readings are above: Ammonia = 0, Nitrite = 0, Nitrates = less than 20 then you need to do a large water change and get the toxic substances out of the water. (50% at least but 75% if the readings are high)
What other fish are in the tank with the Discus?
Rose
