Vanilla Orchid questions

[Fusion94]

So, i have a couple vanilla orchids i would like some advice on. In zone 9A so it spends time both on our back patio and in a greenhouse. When in the greenhouse it gets 80* temps and 80% humidity and 6 hours of lights. The larger of the 2 just recently stopped growing from the main vine and split off about 5 nodes down into a new vine. This new vine is more yellow than the rest of it. Any idea what could be causing this? should i cut off the old section and try to get it to root again? Also the main pole is stuffed full of coco fiber. doesnt seem to be holding onto water very well and thinking about switching it all over to coco chips with peat moss and some compost to help. Would anything else be a better solution for this area? Also i would really like to push alot of growth this summer if possible. I just ordered some kelpmax and msu fert. anything else i should toss in? and finally, should i just drench
h the whole vine weekly or do daily foliar sprays with a very weak solution?