Its been a long time since I had small children to make goodies for. Except for grandchildren. They like hard tac when it is fruit-flavored and contains citric acid to make it have a tart taste. This candy can taste flat without citric acid in the fruit flavors. But don't add too much.
Citric acid is hard on the stomach if too much is added.
But this is what makes that tartness in candies. It comes in liquid or powder. Sometimes I pour the cooked candy into molds. I like the simple white plastic ring ones. Just add a sucker stick.