Sandra - is that large bark you have this phal planted in? In my experience with 35 or so phals, they only get droopy leaves from lack of water - both underwatering AND overwatering can cause this. Of course poor roots effectively would = underwatering, even though you may be overwatering. Since you can see the roots and have verified that the roots are in good shape I think the issue is most likely the water absorption properties of the bark you are using. I have taken a fairly large phal in the past with good roots and stiff leaves and after potting it into new bark and watering once a week for 3-4 weeks have noted the leaves getting droopier and droopier and even slightly ridged from water loss - with the roots still being in good shape. This was my last phal in bark (at work) - it had previously done fine in bark - but now seemed to be very very slowly dessicating. Hmmm. I have said this before - not all bark is created equal. I believe this particular bark was not retaining adequate moisture for the roots and associated plant. I decided to put it into my coir mix and BOING! EVERY LEAF within a week was sticking straight out like stiff plastic!
Now instead of watering every week I water every three weeks or so - and the leaves have continued to remain stiff and perky.
Something to think about - may or may not apply to your conditions and plant..............