I generally feed my boys and girls 2-3 pellets twice a day...I'll throw blood worm or mosquito larva in there every once in a while for a treat, so if you only feed every few days your definately not over feeding (unless yo give him like 6-8 pellets in one sitting but it doesn't sound like it). He might be constipated in which case try some aq salt or IAL (Indian Almond Leaf). He might not eat for the next couple days because he's used to only eating every once in a while.