I have found that this is the best recipe for making your own nectar.
1 Part Sugar
4 Parts Water
Boil 1-2 Minutes
Cool & Store In Refrigerator
Never use honey or artificial sweeteners! Honey ferments easily, and can cause sores in their mouths. Artificial sweeteners have no food value. DO NOT use red food coloring in your solution, as this could be harmful to your sunbirds. No testing has been done on the effects dye has on birds. Do not use honey because it spoils easily and has bacteria in it that can cause a fatal fungal tongue disease.
Most feeders have red on them and that should be enough.
Bring water to a boil over low heat and stir in the sugar. Boiling kills mold spores, but do not over boil. Cool the mixture and fill the feeder. You can store excess water in the refrigerator.
Your feeders need to be cleaned, and nectar changed every 3-4 days–more often in hotter weather. If you see black spots inside your feeder this is mold and you will need to scrub it out with a good bottle brush, but if you can’t reach it with a bottle brush you can add some sand with water and shake the feeder to remove the mold. You should never use harsh detergent to clean your feeder. Rinse out each time you change your nectar with hot water, and if you do this on a regular basis you should not have a problem with mold inside the feeder. Don’t fill the feeder more than half full, because they won’t be able to drink it all before it will need to be changed.
You will find that feeder activity slows as more flowers bloom in your yard. Do not panic! They prefer natural nectar over what we give them in our feeders, so they are still around, and you will see them at your feeders more often, as the blooms start to diminish