for the fim'ing, you should see them start putting out in about a week... as for the deficiency, i realy don't know... mine will show a little red/purple, but i don't pay it too much attention unless the plant is showing other signs of discomfort... but for seeing the effect, you should notice a change in the new growth first.

i was wanting to see an overall pic of the dryer, as i have a dead one and though this to be an EXCELLENT idea! so, pics would help me out with that one...

kp