Thank you all very muchI actually just got some Kuhli's for my tank, I've only had them for less than a week and I'm already in love!! I have a higher ph too and they're doing just fine. I've been researching them like crazy for the past couple of months, and like jkkgron2 said, a lot of owners I've read about say that they do best in a group of 6 or more.
From what everyone says, it makes them feel safer because of their numbers so if you have one, it might become more personable with more. Mine are out in about all the time, exploring every part of my tank. It's so fun to watch their school, such funny fish. I promise you and your kids will love to watch them!! I hope this helped