i was wondering if i just have a shy piranha....cus all it does is chill in the back of my tank and no matter what i have done it doesnt hardly do anything. ive hardly ever seen it eat. ive dimmed my light, added plants, wood, floating plants, and it still doesnt do much. just wondering if there is anything else i can do? its in a 28 gal, its 5 inchs, and ive had it since it was small enough to eat brine shrimp.