Why are my leaves curling ?

AK48 2 weeks into flower. Just started curling ?

classic "N" nitrogen toxicity (to much) presents it's self as dark green colored leaves and also the leaves look like a "claw", this is a common issue, Just flush for one week:" Remember once you see a problem you are all ready two weeks behind in fixing it" - if in flower stage the plant does not need much "N" at all Hope this helps!!!! Stop "N" use and increase "P" & "K" ( "P" being in greater amounts of "K" and "N" should be lower than "P") plant need "P" for flower development and "N" for vegation growth

Great thanks for you help. Guess I need a different fertiliser.
Thought it was that or a ph problem.
Thanks again.

NPK is 5 4 11.

just looks like that one top is affected wouldn't N t0xicity be more uniform?

check your pH. I would start there. if it's out of range fix it, if it's in range then you might be looking at...
You have some leaves in the middle that look like a pH problem.
Bottom growth looks way to green.
Leaves are clawing, like was said (N) toxic.
Leaf edges are curling up, I can see on a couple a leaves. That could be a magnesium def.

harris hawk said:

classic "N" nitrogen toxicity (to much) presents it's self as dark green colored leaves and also the leaves look like a "claw", this is a common issue, Just flush for one week:" Remember once you see a problem you are all ready two weeks behind in fixing it" - if in flower stage the plant does not need much "N" at all Hope this helps!!!! Stop "N" use and increase "P" & "K" ( "P" being in greater amounts of "K" and "N" should be lower than "P") plant need "P" for flower development and "N" for vegation growth

Click to expand...

Not true. Plants actually need low-moderate amounts of P during flowering, but still need consistent amounts of "N" to retain healthy foliage and thus healthy plants. Also, their TRUE requirements for K are actually higher than their requirements for "P" during flowering. I would never recommend stopping the use of N, but curtailing N for awhile until the plant shows a need for more nitrogen is probably the best bet. In addition, different plants have different requirements. Some are N hogs during flower, while some aren't. It's all about "reading" the plants.

You are fight a little 'n' will not hurt, just perfere to use no "n" and good amounts for P &K. Thnaks for you input, I learned something new, you know - comes down to personal choice. PEACE