Help! bud blast on noid phal but spike stopped budding

[Orchidaceae]

Hi all,

I'm staying in the UK right now, and received this noid white phal as a gift in November. 2 days after it reached my room, it experienced bud blast, and almost all the buds dropped off. (definitely change in environment, temp of room was at 24C then)

2 months after that, most of the original flowers still have not withered, and are in fab shape. However, the tips of the spike are still dormant and I wanted to figure out how to reinduce budding in these spikes again.


Here's the condition of the plant:
Root system - excellent. Lots of thick fat green roots throughout the pot.

Leaves - green but neither dark nor light.

Spike - 2 large spikes, of which 1 has a side branch. All experienced bud blast, and all have dormant tips.

Mix - unknown?


And here's the condition of the room i placed it in:
Temp - 23-24C(73-75F) by day, can be kept at 22C(72F) by night. However i understand that phals thrive when temp fluctuates? So at night i leave it at my window, which is about 16C(60F).

Light - mostly artificial light under a fluorescent desk lamp. Not very strong, but definitely better than windowsill (west facing, in UK weather = <1h sun). Allowed to have about 12h of light per day.

Water - watering every 4-5 days, by complete dunking into pail (keeping crown dry). Is hard water ok?

Fertilising - only done once so far. Using a heavily diluted20-20-20 fertiliser.

How can i alter/improve these conditions? Pls keep the comments coming Thanks!