Cool. Found a prob identical to mine. Hope we can find an answer.
I'm in FFOF currently running the FF trio. Had this problem last crop, interestingly enough, after switching to FFOF from Kellogg's. i grew in MG Organic my first grow and have never seen better looking plants for the most part of the grow(harvested about 1.7oz/plant dried under cfl, now under 600w hps). The flush, or lack of being able to, was the reason i stopped the MG soil. Switched to Kellogg's for the next two and went with just Grow Big and Tiger Bloom with disappointing results. The 4th one i switched and developed this symptom but was able to harvest although dismal due to environment issues in a new room/house OR something i did/didn't do. No way to tell. NOW i have control of the room and have been vegging once beautiful Kryptonite clones for about 4 weeks now and THEY have developed this symptom. SOOoo, i am intrigued and a little baffled but then again, i'm also pretty new to the show.
Sub'd.