I used to tell people to switch to a higher phosphorus fertilizer the moment they saw flower spikes start to develop. The prevailing thought among growers was that blossom boosters with those higher middle numbers increased flower count and size.
Recent research on Phals, though, has shown that switching to a blossom booster not only doesn't increase flower count or size, it actually *decreases* them. Here's a thread with more info: http://www.rv-orchidworks.com/orchid...2019#post12019
So Traci, at this point, I don't think I'd switch. Just keep using what you're using, something balanced, or with higher nitrogen if you're growing in bark mix (decaying bark supposedly binds the nitrogen, leaving less available for the plant, but I don't know if this has actually been verified or is just a myth.)