Stress can cause this, The pistols go thru stages, its quit regular to see the pistols turn red and new ones start around 5-6 weeks into flower, some strains a lil earlier... What starin are you growing and how long have they been in 12/12?
White Russian SS. Fuck i can't get the harvest part right.. Really look lots greener and less dusty in like 4 days.. Been in flower since 8/10. 65 day strain... Also white flies are taking over after 2 weeks of keeping them at bay...
ok...you noticed its greener...Thats a prety good sign of maybe to much nutes, wich can cause stress.. i find late in flower its always a good idea to start cutting back on nutes, Let them use some of what i stored... What ppm's are you at??
To high. What I thought exactly... Got busy and did not top off for three days now flushing.. was at 1950ppm all bloom nutes..... Think I screwed them up when I flushed for 3 days with water then renuted... Stupid I guess...
it happens man..no worries... just get the ppm down to about 800 and they will be fine.. they will start to grow agian.