Keep on the 7 day schedule. A 500 g can easily handle a small rat. and I don't see how 3 mice are over feeding. Unless the mice are humongous. I would keep as long as they are eating good. Everything will change when the temps start to drop, and then it's going to be...."why aren't my snakes eating" lol. Mine were gaining close to 100 g's a month when they were younger too. It's so nice to have hungry balls.