Well, the pH for jewels aren't all that different from mbuna, and the acceptable range overlaps by quite a bit. I'm sure they'll be fine.
They've been in the tank now overnight, and everyone is getting along just fine. The yellow labs were kinda ticked at the red zebras - the jewels kicked the zebras out of their cave, and they tried to move in with the labs. They nipped at eachother for a few hours, they all found new caves, and away they went.
Interesting though, the zebras took caves near the top of the pile, and yellow labs took some in the middle and the jewels dug their own cave in the sand. I wish I knew what was going on in their head
BTW: How would Kenyi cichlids get along with the labs and zebras? The LFS has some really nice female kenyi's, and they're all from the same