Phals take temperature change as a signal to get ready for flowering.
Your phal has old spikes.
Did you get it in bloom in the summer?
Commercial greenhouses control temperature to manipulate phals to spike anytime of the year, hence we can buy beautiful phals in bloom anytime of the year.
Usually, phals will bloom from mid winter into spring time.
When you buy phals that are in bloom at "odd" time of the year like yours, summer time, it needs some time to adjust to its new environment.
I have bought phals in bloom in the summer, and almost none of them spiked again in the fall of the same year but many of them bloomed from old spikes (I do not cut off spikes unless they turn brown and die on their own).
Your phal will most likely wait until the fall of next year to spike and bloom. From that point on, it will spike in the fall each year.
Regarding the light, you did a good thing by moving it to a brighter location.
North window works as long as the window is large so there is a lot of light coming in and there are no buidlings or trees outside the window blocking the light.
With higher light and phals are no way low light plants, the blooming performance will be enhanced greatly.
Now, regarding watering, you don't just water every 7 or 10 days. You have to find out how long it takes for your pot to dry out to water it again. Only then you can have a good idea of how often to water a certain plant of certain pot size in your growing conditions.
If your phal came in a clear plastic pot, you can easily see how dry the pot is inside.
Water copiously or I like to soak to save water and to let the plant drink up as much as it likes.
Let the pot to dry out before watering again.