I have my jack which is about 3.5" in a 55 for now with my 7.5" oscar and a 2" meeki. And now for a couple of days now he has been very scared and wont swim up to the front of the tank like he use to, he will go and hide under the filter. He now doesn't eat very much, and he use to eat a lot. I think there is something could you please help.