My newly aquired 8" Oscar won't eat either, it's been a couple of weeks. He's recovering from HITH from previous owner but he's about all healed up. He's just not eating and spits out pellets I give him. I don't like to let food waste because it will make the water bad. I'll just let him be, he will throw a temper tantrum once and awhile, maybe he's trying to tell me something.