Adding an automatic fish feeder to your reef tank will let you feed your fish when you are on vacation, or if you have fish that require multiple feeding a day, an auto-feeder doesn’t forget. The Lifegard Intellifeed is simple to program and mount to your tanks rim. Every Intellifeed can accept batteries, or powered by an external power supply that plugs into your homes wall outlet. The first thing you will need to do is either plug in the Intellifeed to the power supply or place 4 AA batteries into the auto-feeder to power it up. After the LCD screen turns on you can set the time. After the time is set, you can then configure the feeding schedule, press and hold the SET button for 3 seconds and you are then programming feed cycle one. You can choose how many rotations of the drum you want to revolve for that period, then press the SET again, and you can choose the time that you want it to activate. Pressing the SET button after the time is set will bring you to the next feed cycle program. A couple of tips with any auto-feeder is to do some test rotations to see how much food will be dispensed per rotation and adjusting the slide to have more or less food dispensed per rotation depending on the needs of your aquarium. The Intellifeed does not have any built in battery or memory saving if power is lost it will lose the current program that you have set. If that happens, you will need to re-program it. We highly suggest using the standard plug in power supply along with the battery option. That will keep the feeder running in the event of a power outage, and also save your programming too.