I know I have also read different reports regarding using UVB during flower to increase potency. While it may not improve yield, apparently it will help flowering buds increase potency. I am planning on buying a couple bulbs from the pet store (I know I see UVB bulbs when I buy regular basking bulbs for my leopard geckos), and adding those to my light array. I will have to read more about how often the UVB lights should be on and other details.