I feed my adults every day too, just a little bit. Sometimes if i am tired or out for the night i will not feed them and do not get too upset because they will survive quite a while without feeding, and it is recomended to feed them every few days. I dont think its absolutley bececary to have a feeding schedual or anything, they are oppertunistic feeders in the wild anyway - they eat when they can get it. Wile a few off days won't hurt them neither will feeding a bit every day, its really what suits you best because your axolotl will be healthy either way. I think Carsons way of feeding is a good suggestion