I do similar for fertilising ---- one quarter to one third packet-recommended strength, and I do that just once-a-month.
Take a look at this
link here ----- which shows that it's not necessary to just water the roots of the phalaenopsis.
For tropical conditions, we can use anything like rocks or pebbles etc. As long as the orchid gets enough light and enough duration of light each day, and as long as the temperature is nice and warm - so that the roots don't get cold and watery for long amounts of time, and if we avoid still-air environments (ie. have some gentle air-flow nearly all the time), and if we avoid drowning of roots - then that gives the orchid a great chance to do well for very long times.
In the pics at the link ----- notice the pots sit on drainage grates, which keeps the bottom of the pot above any drained water. And while it can't be seen ------ the pots have good size drainage holes, and a good number of holes ----- down at the bottom of the pot. They're just regular plastic garden pot-plant pots.
For the phalaenopsis orchids, and other orchids that I grow ------ I generally apply water into the media toward the OUTER regions of the pot, which gives some breathing room for orchid roots, but also allows roots to get moisture/water without drowning anything.
I think your set-up looks ok. Just don't allow the bark to become super wet and super cold. Maintain a nice growing temperature. And if the light level is a bit low ----- then consider providing a little bit more light ---- and more duration of light per day.