I use five of these on 4 tanks to feed my fish daily for over 10 months and they simply work. The food is always dry, and the opening contains a hinged door that opens and closes when it spins. I've never missed a daily feeding and they are perfect for when I go on vacation. I use them to serve fish sticks, granules or a grind granule/flake mix. The flakes should be grind with granules to prevent clogging. Before relying on the feeder during vacation, I suggest testing and monitoring them for several weeks before relying on your ability to properly set them up. Its best to test them before attaching them to the tank.Go in vacation stress free, my 17 fishes were happily feed twice a day for 7 daysDescription says it works with flake foods but it does not. However it does work well with the right food.I filled this thing up with flake food a couple months back, charged it up, and it's been going ever since. My worry about short battery life was unwarranted, it holds a charge for a long, long time. Perfect if you're going on extended vacation. Plus, flake food doesn't get moisture and stick. Massive win!Easy to set upCan have multiple times for feedingDigitalBattery lasts veeeeeery longvery goodI have this on the tank in my classroom. It was hard for me to set the time. Well I'm assuming it dropped food in there considering we are out on weekends, spring break, xmas, thanksgiving and other days and my fish survived.I went out of town for two weeks and set the schedule on this machine for two feedings a day and it worked! I need to study more how to control the quantity of the food that comes out aside from closing the opening to as small as I could. Otherwise WAY too much food dumped into the tank. But I am thankful I was able to use it! Easy to program too.Nice and good quality product, quiet operation, and easy to program. Adding a bottom plate accessories as another installation options to balance the weight and make it more portable when cleaning the tank lids would make it more user friendly.Nice little fish feeder works better then any other fish feeder I have ever had this one is really better then alot of other fish feeders out there great price and works greatFast shippingEasy to setup and install.Work great with fine/powder food (I use bug bite)Motor is realy silentI will continue to test to see if it keep the good time/resist humidity.But it's a great option when you go on weekend or vacationFish feeder is used in a 33usg aquarium. Bargain batteries lasted 6 weeks @ 3 feedings per day, one rotation. It is used for flake food, with no moisture problems so far. I like the manual feed option. I liked it so much , I bought a second one.