Yes, you should.
How did you drop the pH to 6? Is the pH so low because you plan to spawn these discus?
Is this a raw new tank? Any detectable nitrite is an emergency, as they are highly toxic.
At that pH very little nitrification is taking place. Do you have plants to take up the nitrogen?
The cloudiness is a bloom of bacteria and plankton, unless you have very hard water and have used phosphate-based buffering to drop the pH.
You give very little information. What is your GH (total hardness) and your KH (alkalinity), for a start?