Can't quite figure out what to do for Phalaenopsis

[alsorchids]

Phillip; I can honestly say that it was raised on weekly watering and the only change was in fertilizer regimen some months ago from biweekly to weekly. Medium has been changed two or three times in those 4 years. During its decline I stopped the fertilizer for one month and after the Fungicide bath and repot in new medium bark I used Dyna Grow Root Tone every two weeks or twice total. Now I am back to weekly watering when dry and Weekly fertilizer in the last few weeks. Using fish emulsion with seaweed and MSU Fertilizer for Well Water at half strength. I have a new root under the media, but today two of the five remaining leaves are yellowing. Any suggestions please.