Masdevallia angel fling- yellowing spike :(

[Call_Me_Bob]

i have had this guy for about a month. he started spiking about three weeks ago. and has two new growths and this spike, all growing nicely...until now.

the spike is truning yellow. it looked fine last night, but i was super tired, so i might have missed it. originally it had been a nice green color, the same as the rest of the plant

please help! this i my first masdie, and im super nervous. by the way, im watering with filtered tap, if i can. ive only watered with normal tap once or twice. but i emailed j&l and they said that tap would be fine. the ph of the tap is 7 and the ph of the filtered tap is 6.5