Hello everyone. I'm new to Oscar fish, and pretty new to fish keeping in general. I have a 40 gallon breeder that is cycled; 0 ammonia, 0 nitrites, 5ppm nitrates. I now know that it will eventually be too small, and I will be getting at least a 120. I brought home a small Oscar about a week ago and it still hides anytime I go near the tank. It does still eat as long as I'm away. How long does it take for them to act normally? Everything I see online says a couple days to a week. Should I be concerned?