Mix water, Sure-Jell, and Kool-aid together in a large pot. Bring to a boil, stirring constantly. Stir in sugar. Stir and bring to a full rolling boil that can not be stirred down. Boil for 1 minute, stirring constantly. Remove from heat. Quickly skim off foam with a large metal spoon. Pour into jelly jars and seal.
Make sure your jars seal properly.
Our favorite is Mango-Pineapple. I use mango Kool-aid and 1 small flat can of crushed pineapple, drained.