Is this normal discus behaveiour?

ok so my tanks water yesterday was replaced with pure RO water and i bought discus on the same day and my ph is fine at 6.5ph, my nitrite is at 0, and my other fish such as my featherfin catfish and clown loach are healthy and fine. i can tell they are uncomftable being introduced to a new tank so they go abit dark. i have 2 and they swim close together and just like sit at different levels of the tank