The big plant is now showing a phosphorus deficiency due to some of the leaves purpling. Granted I've only flushed it once I'm not quite sure what to do.

Do I let all of the growth just die due to a deficiency?
Do I give my plant JUST that one nutrient?
Do I give it a good fertilizing one last time?

I'll give some more information on the trichomes in a minute, I may have to bust out my old microscope and trim a leaf with some trichomes on it.
If I had to give you a percentage on the hairs on each bud turning brown, I'd say at max 10-15%.

Help! XD