Hey there, I think as far as the tyree watermelon chalice, generations of growth has shown that it really retains its color, regardless mh or pc. My watermelon is in a system with 2 250 watt mh but, it tucked in the back under a ledge where it is predominately shaded, so not getting much light or flow. I think if you invest in halides and any coral you have doesn't like much light, you could always create some barrier or shade. With pc, you can't create more light. I understand your concern, those watermelon chalices are not cheap, but for that type of money, try to get a tyree, only because that strain has proven to maintain its color. Hope this helps. Al