So riddle me this batman. I bought a new discus two days ago. The discus is now my second largest one. so i transfer him into the tank and i could tell he stressed out hes hiding up in the corner of the tank and not looking to good. also one of my smaller discus keeps nipping at him. so just in case i check my water levels. 6.6 ph 0 ppm ammo. 0 ppm nitrite 20 ppm nitrate 83 degrees temp. so after that i shut down the lights for the rest of the day and night. i wake up yestersday the new discus has all its color back looks awesome is hanging out with the other discus. happy happy joy joy. so a hour later i walk pass the tank again and theres the new discus up in the corner all stressed out again and the other smaller discus keeps pecking at him. so i call the pet shop and ask the guy about it he says to move everything around in the tank let it sit for a hour or two then shut down the lights for the rest of the day. so i do this and wake up this morning turn light on and the discus looks great again hangin with the others. hour goes by again and i look theres the discus up in the corner all stressed out and the smaller discus still messin with him here and there. any ideas guys? should i shut down the lights again or should i just let them be?