I'm pretty sure you're talking about Laetacara curviceps, right? They used to be just the Flag cichlid, but they are blueish in hue so maybe they've been renamed?
If so, they come from large areas of the Amazon with diverse water parameters. In general, they will do well in a pH from 6.5-7.5, KH & GH on the lower side (but most are not wild and can handle much, much higher KH & GH), temp 76-82.
They're hardy, peaceful and just great little cichlids. I've had curviceps in the past, have their cousins L. dorsigera now, and highly recommend either (PetSmart is selling mislabelled dorsigera claiming they are curviceps - that's how I ended up with dorsigera).
Eric