It's hard to say for sure with out knowing what your growing conditions are, light, temperature, humidity.

I see you are in Va. so I would guess that it is pretty dry this time of year. To me they appear to be dehydrated. You say you water once a week but how much water? When I water my goal is to soak all of the bark in the pot, then it dries out over a few days. If your humidity is low and your potting media becomes very dry it might need to be soaked for a while to re hydrate.

On the other hand if your potting mix stays damp for too long it breaks down into compost which then suffocates the roots. When the roots die the leaves start to look dehydrated, some people see this and start to water more which makes the problem worse.

When was the last time it was re potted? The level of the bark in the pot looks a little low. Sometimes the bark on top looks fine but down at the bottom of the pot it has decomposed.

James, thank you! I've recently re potted them. I'll go ahead and give them a good soak and mist.

Agree with James. Terribly dehydrated. Soak those pots until the bark holds water. The bark you used is really too large for Phals. But if you water properly, they should recover.

Jane