I wouldn't advise that anyone use urea on cannabis. i have used it before growing chilli to excellent success ,it needs to be watered down and has to be used very quickly.
No its not something that comes up often but i see it from time to time in forums etc. I like to see us as like guardians of our ladies that watch over them like a god and give them the most wonderful life and in return they bestow a bountiful harvest to say thanksYou know, of all the things we have to worry about and prepare ourselves for in optimising conditions and environment for these wonderful medicinal herbs - cat piss terrorism isn't one we often discuss ...
Holy crap man, that's a weird one,... 100% sure this isn't anything that got spray, pee, or spilled on it, or light burn... and the pattern is very much K related.... See how the teeth tips are progressively worse toward the leaf tips, until more and more of the leaf is browned out? Yoz, did this happen during the day, or overnight? I don't believe it's a coincidence it happened after that increase in feed amounts along with the water, and it follows that it's very unlikely a defc., more likely a toxicity problem,... K can be bitchy mate, and the symptoms for both can overlap, and get muddied by other co-issues affiliated with toxicity,... the speed that this happened at though didn't allow other symptoms to manifest-? The speed that this happened at, and the browning of tissues,....yeah, more and more looking like toxicity... could be it was right at the edge, and that last jump in feed tipped it over. It's maddening to see other plants with minimal or no symptoms, but each pot becomes it's own little "system" deviating from the others, though they all might be close... toxicity with K is accompanied by low pH in the root zone, so check the pH there mate,... Nutes and conc. noted, and doesn't seem overly high,... are you feeding every time (looking at cumulative affect here)... Your EC and pH= 
Is that for the nute solution or just the water alone? 2.3 EC is massively high-- 1.0 EC= 700ppm in Aussieland, right? How did you get it down to 6.6 pH? I'm looking at all ionic/mineral inputs here,... Worse, the warmer weather forces the plant to pull water like crazy, forcing further absorption of nute elements, accelerating build-ups internally,... let me know about the water chemistry, etc...
Hey Yoz!
I don't believe it's a coincidence it happened after that increase in feed amounts along with the water, and it follows that it's very unlikely a defc., more likely a toxicity problem,... K can be bitchy mate, and the symptoms for both can overlap, and get muddied by other co-issues affiliated with toxicity,... the speed that this happened at though didn't allow other symptoms to manifest-? The speed that this happened at, and the browning of tissues,....yeah, more and more looking like toxicity... could be it was right at the edge, and that last jump in feed tipped it over. It's maddening to see other plants with minimal or no symptoms, but each pot becomes it's own little "system" deviating from the others, though they all might be close... toxicity with K is accompanied by low pH in the root zone, so check the pH there mate,... Nutes and conc. noted, and doesn't seem overly high,... are you feeding every time (looking at cumulative affect here)... Your EC and pH=
2.3 EC is massively high-- 1.0 EC= 700ppm in Aussieland, right? How did you get it down to 6.6 pH?
