Best shade screen (30% or 70%) for Phalaenopsis? outdoors in West Central FL

[birdwomn]

I am currently using a 30% shade screen on my lanai for all of my orchids, but am wondering if I should switch to a 70% shade screen for the Phals as a few of them have a bit of purple in the leaves. I recently arranged them in hanging wooden baskets which provides better drainage.

As stated in the title, I am in west central Florida, about 4 miles form the beach.

Any thoughts would be appreciated.