Phal potting medium change

[missfitxo993]

Hi everyone, I have been into orchids sonce 2007. The only one that I find hard to care for is Phal. Have wild orchids from rainforest to hybrid and haven't killed any. I like Phal though it do not like me.
I bought 12 phals and their potting medium is coco coir/peat potted in soft clear plastic container. I have checked the first five and the roots are very bad most are black and mushy. I repotted it in clay pot with holes around and i used coco husk chips, charcoal and some sphagnum moss mixture though there is only 2 small roots aroubd 1.5 inch left, sone have more but 3 have only 2. The other 7 have very good roots and firm leaves.
Now I would like to ask will this chamge of potting medium affect the Phal? I am in the Phil and I grow the phals in my Balcony facing East. The 7 with hood roots are in bloom the other 5 with bad toots I cut the spike to help the plant get more roots and leaves. Their leaves are a bit soft but green. Thanks