A new one on me

[bigboo]

I've never seen a leaf do this. Gorilla purple in 2nd week of flower. Soil grow using Advance nutrients. Lights kept 18 to 20 inches above canopy. Temp kept between 72 and 80 F. Humidity at 40 to 45. Any thoughts?

 

[Ninjadogma]

I sometimes get those when revegging and sometimes it just happens out of the blue... My best guess when it happens randomly is a broad mite was in the top munching when what became the leaf was still about 1mm in size and the leaf still grew undeterred, but thats just a guess... because it's localized.