I have 3 male fighting fish - in different tanks and they all turn their noses up at beta food, but as soon as I get out the gold fish food out they begin swimming around their tank and when I hold a piece of food inches over their tank they jump out and take it out of my fingers, the guy at the pet shop said they will ONLY eat beta food? is it bad that I'm feeding my fish these? they actually seem brighter in colour and more active these days since they've been eating them? am I killing them? help please ...