What is this?

It appeared after an application of Old Age Grow. No bugs, Dr. Doom took care of the bugs after a couple of treatments. This came way after any sign of bugs...
Fig 1 is the lea top
FIG 2 is the underside of the same leaf
Fig 3 is the whole plant

Did you water/spray the foliage while under a hot light? More likely the treatments.... keep an eye on the new growth. It will be fine if it was caused by some type of spray.

I may have...I will try to watch that.

How they doin' Zig?