Agree with Ursula, this isn't a fungal infection. Nothing you need to do, and the fact that it has a new leaf that is healthy is a salute to you that you're taking good care of the plant. Relax and enjoy it.
Once the blooms are finished then think about potting it into new medium, and a basket or well-vented pot. Don't cut off the bloom stem until it turns completely brown. It may branch and give you some more flowers, or even a keiki.
If you live somewhere with warm (not too hot!) summers you may consider letting it grow outside once the night temperatures are above 55deg. or so. A shady place hanging under a tree would be excellent. Btw, when you re-pot you should let your Phal hang over the edge of the pot so that the leaves drain well when you water it or it rains. Phals normally grow with their leaves hanging downwards, and the flowers naturally cascade downwards as well. This upright habit with stakes etc. is something the growers do so they can package them in boxes easier.
