Do I need to constantly feed my starter?
No, in fact, you can ‘overfeed’ it’ If you bake daily, feed it on the worktop before baking. If you bake weekly, then feed weekly. Use half and save half. Half goes into the bake and half goes back into the refrigerator with a snack to keep it going. But if you don’t bake that often, your starter will be happy living in the refrigerator between bakes. If you go on holiday for a while (a month, for instance), freeze it until you get back.
What do you mean by ‘overfeeding’?
When you feed your starter, you add flour and water, thus reducing the number of microorganisms in the starter. The starter then has to start rebuilding. If you keep feeding before the rebuilding has finished (and the starter is at its maximum) by feeding too often or giving it too much food, then the starter will fail and lie there exhausted. It’s one of the reasons why people kill their starters early on.