I finally found a hummingbird feeder I really like. It has a large opening so it is much easier to keep it clean than the ones with the little dime size opening. But it still gets moldy. After many attempts to get it really clean by hand I decided to put it in the dishwasher. Did I mention it is plastic? It was in the bottom of the dishwasher and got too hot and melted and warped. This morning I am off the the bird store for another one. Hope I find one I like as well. Wish me luck.