RH, I have a simple answer. Grow the Phalaenopsis by growing the best roots that you can and the most leaves that you can.
It is not about flower height really. Any that bloom under the lights and have flowers up in the tubes, should be taken out from under the lights and displayed around your home.
With Phalaenopsis, the leaf color tells you if the light is correct.
If the leaves are:
Granny Smith Apple Green then the light intensity is correct.
If the leaves start to get to be a real yellow-green in color, it is an indication of too much light intensity. Lower them by 3" and re-evaluate after 6 weeks.
If the leaves get to be a darker forest green color, they can be closer to the tubes. Move them 3" closer and then evaluate in 6 weeks.
I hope that this answers your question..
