I have some juvies mixed in with adults in 2 of my tanks and they are doing great, but they're not red zebras. (Rusty juvies with Membe Deep. Albino Greshakie in my 125 mixed tank.)
Usually smaller Mbunas will be brave, and quick, when it comes to food. But you can try this if needed: When I feed flakes, I put a pinch at the top to get the adults attention. Then, immediately move over a foot or two and shove that pinch down in the tank farther.
When I feed pellets, I soak them in a lil tank water for 10 minutes so they get soft. I pinch 1/2 of them in half, and those sink so that I can make sure the juvies are getting enough food without over feeding the adults.
I alternate between flakes and pellets right now. (Haven't made any frozen veggie cubes lately.) On day 6, I don't feed at all. Day 7, I feed shelled peas, the frozen ones. Helps to clean them out. Just drop them into a coffee cup of water and heat them up. Squeeze them and they pop right out of the shell. They get used to that fairly quickly, so don't worry if they don't seem to love it the first time. Then the next day, I clean the tank!
Soaking the pellets so they go ahead and swell up before feeding, seems to help cut down on bloat too. It surprised me to see how much floating pellets swell up! Some of this is probably stuff you already know, just trying to be helpful.
