I don't always have success with semi hydro for my paphs. I've lost enough paphs that I've wanted to cry. I've learned for me, in my culture, small seedlings and flasklings don't do well in it. There will always be the exception to the rule, but the paphs that have died for me have been on the small side. I also cut back on the watering and fertilizer in the winter.
I also have found one brand of leca does much better for me than any others. But, unfortunately this leca has become available sporadically and at great expense to ship. So, I'm actually in the process of transferring many of my paphs to a chc mix. So, I'll be joining you in the normal cultural method.