I know this is a common topic but I am confused (also common).

My sister bless her heart, feeds her phals 25-10-10 and gets non stop flowers. I feed 19-31-17 and get leaves and roots. I have checked and have found that, to me the numbers don't match what is happening.

Also she has her phals in a window that gets direct sun (right up against the glass) for several hours in the late morning with no ill effects. She uses a bark mix and I use moss. She soaks her roots when dry and I do the same but I also spray them daily.

My flowers last about two or three months and hers are six month or more. I have even given her some of mine that have stopped blooming only to have them start again.....