Quarantine Tank

I decided to use the 15gal columnar tank as a quarantine/hospital tank. Initially I used it to age water with the HOB filter, an air stone, and a heater running. One day I tested the aged water and noticed a nitrite spike. Nitrite is the second phase of the nitrogen cycle so that means the nitrogen cycle somehow has started in the the tank. Perhaps because of the running filter. To confirm this, I tested the water straight from tap and nitrite shows up negative. At this point, I can't use the water in there to do water change because of the nitrite. I think it is best to let the tank  finished its cycle and use it for a quarantine/hospital tank. I sped up the cycle with Tetra SafeStart Plus and place a sponge filter in there to enhance the biological filtration. Tested the tank 7 hours later to find the the nitrite has disappeared and now with a little bit of nitrate. The cycle is complete.
It should be safe to add fish.

ACCLIMATING NEW FISH
Floated the bag for 30 minutes,
Opened the bag to mix some of the tank water in.
Let it float for another 10 minutes,
Added more tank water into the bag and waited a few more minutes.
Released the fish.
All steps with the tank light off.

As part of the quarantine process, I dosed the QT with ParaGuard. This doesn't stain the water or alter the PH.  ParaGuard supposedly help clear any parasite or ich a new fish might have.

 My quarantine tank set up: bare bottom with HOB filter, a sponge filter, a heater, and a fake plant to help the fish feel safe. 

New yellow discus in quarantine, 2/7/2015