Alannanoelle,
If you only have phal type bark - you can just cut it up into smaller bits and mixed with the stuff you already have.
I would wash it and keep the 'bits' pebbles etc & repot with this mixture (If this is all you have).
I am not an expert but my paphs (6) are all potted in slightly different mixes of medium...Although they all contain Bark,spagh,Leca,Perlite,gravel (from the beach) & Crushed Oyster shell.. I have had most of them for over 2 years and they are all growing
(albeit S l o w l y) and I have 2 flowering for the first time this year! In my growing conditions I have just tried to always keep them a bit damp & not let them go really dry for too long..Although I am a great believer that It's "better" to be a bit drier one more day than "wetter".
I use a wooden skewer in the pots to determine who needs watering - as they all 'dry' differently in my different mixtures!
Your plant looks very pretty & healthy, Good Luck!