Thanks for all the inputs guys.
I found that the water was lacking oxygen so I increased air pump power and added a mist air stone. I also added a small wave maker on top to increase water movement. As mentioned, my Aro is back to normal.
Ammonia is 0 or close to 0 since the test tube color is very hard to tell whether it is yellow or yellow with a slight green tint. I am sure my tank is cycled since I use the same filter from the old tank. Just new tank and 50gal new water.
Anyway, thanks all.