UVB appears to be one of the biggest factors in THC production within the trichromes. therefore, i would assume that UVB light is almost useless until thrichromes begin to appear, and is therefore useful right up till harvest
klondike_bar Reviewed by klondike_bar on . Should you use more uvb in the very end of flowering Im using uvb and it is towards the end of it's life cycle ready for harvest. It is in soil, stinkys mix, 12/12 400 HPS, molasses, koolbloom 0-10-10, ligh MG for trace nutes when needed. Everything is going great I added uvb in flower and now it is time for harvest, then fan leaves have started to yellow and trichs show just days left. I have been using the uvb 4hrs per light cycle but I was wondering if I should up this for the last 2-4 days, and if so how much of an increase. Thanks in Rating: 5