yellow leaves with black tips during flowering

i have enclosed two photos of my crop. One is the full crop and the other is of the problem plant. Had this problem before, only once the leaves turned full yellow the buds started to die. hasnt happened so far with this crop only the one plant is starting to yellow, only started during flowering stage and also tips of yellow leaves are brown. plants were in veg for 6 weeks has been in flower so far for 5 weeks, still 5-6 weeks left, plant is big bud. does anyone have any idea why this one plant is like this and does anyone know about the previous problem. i have heard that i need to flush the problem plant out, also a N deficency or over fertilized????????
does anyone know which one is right!!!:rasta:

:0 nice gro man

EXCELLENT!

thats a lot of buddha man, id love to live in that room. as for the other plant, cant help you there, sorry man

my plants are like that too. the yellowing is spreading pretty fast, and it's worrying me. i dunno if it's a burn or a deficiency- i have tried no nutes, lotsa nutes and nothing has really seemed to help so far. so hopefully someone has an answer.

i have a similar prob. looks like the nitrogen i added is gonna fixem up. plants use more N during flower.and my c99 need more N thru whole grow.

Yeah looks great! I also agree that the plants are probably just sucking the N out of the fan leaves.

thanks 4 info happy smoking!!!!!!!!:stoned:

i heard 1 part urine 10 parts water could do the trick.
has any one tried this?:confused:

Ugh please no more urine! Ewww!
Your plants look fine for that far into flowering. I gave you excellent becuase you have great bud development and your yellowing is not going to impact your harvest! Yummy!

yo its all good man they do that when it comes to the end and when the top buds (start to die) u can clip thim off and keep growin the lower part i had one like that and i cliped the top off and grow the rest for 2 more weeks