Don't buy the red nectar-the hummingbird websites warn against it. Use 1 part sugar to 4 parts tap water. Mix it in a pitcher with a lid. Refrigerate any leftover nectar for up to a week or so. Change the nectar every couple days; especially if it's hot. Once it starts getting cloudy, it must be changed. Every other time, take the feeders down and wash them in a mild detergent with a little bit of bleach to kill any bacteria inside of them. I usually have 4-6 feeders going. I've had 10 times more hummers since I read the article and stopped buying the red nectar.