It just so happens that I raise green cheek conures and am handfeeding 5 right now! The youngest is approximately 4 weeks now and eats about 10-12cc of formula per feeding. I feed at 6:00am, 12:00pm, 6:00pm and again at 11:00pm so 4 feeds per day. Some breeders only do 3 at this age. If you feed 3 times a day the last feed would be 11pm and first in the morning would be 7am. They shouldn't go longer then 8 hours especially at 3 weeks of age. I don't drop feedings until my birds refuse them. I start offering cheerios, cooked grains/chopped veggies, small pieces of spray millet and small zupreem or roudybush pellets in dishes when they are still in brooders. I don't offer water in the brooder as it makes a mess and they get all the water they need from the formula. When they go into a weaning cage is when they begin eating more on their own and begin refusing feedings or cutting down on the amount they take per feeding. I also give shallow dishes of water in weaning cages. They will not wean without water.
Some of my greenies wean at 8 weeks, some at 10. I do not rush any of them, they go at their own pace. I have used Exact but switched over a couple years ago to Zupreem Embrace as i also use Zupreem natural pellets. Good luck! Your baby is very cute indeed!
I should note that I do not put into weaning cages until they are feathering and trying to perch on the dishes, etc. which is normally about 5-6 weeks more or less. I keep a heating pad on low under the cage until they are totally feathered and perching. And I NEVER sell un-weaned babies, ever.