I live in a low-humidity climate too. With Phals you want to soak them, then let them almost dry out. How long the drying out takes depends on the temperature.
If you're not sure of your humidity, it might be a good idea to get a cheap thermometer/humidistat at Radio Shack. In my growing room, with a lot of plants, it's usually 40% - 60%.
To raise humidity, have a lot of other thirsty regular house plants in the same room, or have a cool ultrasonic humidifier.
If the bark is old it starts to break down and get mushy in the center of the pot. You can't see this. The mushy stuff never dries out. This is why most people repot plants in bark every 2-4 years.
I would use water-soluble fertilizer instead of the spikes. I fertilizer my Phals at every watering with 50PPM nitrogen fertilizer, which is not a lot. You can read a lot about fertilizer on
here.