Automatic feeders have their place. If you have a large pond and you want your koi to grow as fast as possible, then install an automatic feeder and feed them a high protein food 5 times a day during the whole summer. On the other hand, if you just want something to relieve you of the responsibility of feeding your koi daily, we would encourage you to save your money and find the time to do it yourself even if it is only once a day. By feeding your koi on a daily basis you will become familiar with how they respond to the food. This is invaluable! The first time you feed them and you notice one or more of them responding differently, you know something is wrong. It could be something as simple as your water chemistry is off or something more serious such as parasites. Whatever it is, you will be able to get a jump on it before it becomes a real problem. When you go on vacation just ask your neighbor if he or she would mind coming over once a day and throwing some food in the pond. Most neighbors would jump at the chance. The real advantage of your neighbor feeding you koi while you are on vacation rather than some machine, is that if there is a problem they can call someone.