Ok first off, please fill out the troubleshooting form for better results on the advice people give. However, assuming everything else is right(pH, room temp, ventilation) my guess is a Phosphorus deficiency. The Grow Big you are using is a veg stage fert high in Nitrogen, but has a little Phosphorus in it. The Big Bloom is used for promoting and maintaining a healthy root structure(has very low N-P-K). The third part of the trio is the Tiger Bloom. This is what is recommended during the flowering stage. Fox Farm also makes their water soluble line(Open Sesame, Beastie Bloomz, Cha Ching) that are additives to use during the blooming cycle. These are very high in Phosphorus. By looking at your pics I would assume you are somewhere around week 4-6 of flowering. During this time Fox Farm's feeding schedule recommends Beastie Blooms.:thumbsup::thumbsup:


As far as this being the first time you've had this issue during a grow, I would say that this time you've got a strain that requires more Phosphorus during the flowering cycle. My guess is that each of your previous grows were also Phosphorus deficient, but the plants were barely getting by off the Phosphorus that is in the Grow Big. This time it wasn't enough.