leaf problems please help

hi i have 6 plants indoor grow

600w hps
1 exhaust fan
2 circulating fans temps never above 30 c
medium: canna coco pp
canna part a an b nutes 1.4ec at moment, 4 weeks into flower
canna rhizotonic
cannazym
and vitalink buddy blooming aid.

since the ladies started to flower really i have been picking up wilted leaves that have fell off and now 4 weeks into flower all the bigger fan leaves look as thow they are about to go yellow and fall off, pretty much most of the fan leaves are a light shade of green with the connecting stems going brown like they are just about to die and fall off. the little bud leaves are perfectly fine just the fan leaves. strains are k2 and tangerine dream any help would be great please as i have read all the stickys and cant find my scenario to go off cheers guys

hi the first pic is the only recent one i have without the light being on sorry

Is it from the bottom up mate? Or are you gettin rust spots to start?

with the rust thing only 1 plant seems to have that and its only on about 3 leaves near the top. as for the bottom up thing it is a bit hard to tell as most of the leaves are a light shade of green and it is pretty random where they are yellowing so its pretty much all over if that makes any sense lol

they look fine. you could double check, make sure there is adequate drainage, good irrigation, make sure the light isn't too close...

i think drainage could be ruled out as i have a good inch if clay pebbles in the bootom of each pot, i will move the light up a inch or two as i think its on borderline close, i was maybe thinking it was just part of the flowering phase because of how healty the buds and smaller bud leaves look but then i took about 4 or 5 looks and thought no you definatly have a problem lol

also the leaves just look dry lol

A would hve said u need to get some cal/mag and add that to your nutes.... The totally yellow leaves also look as if the nitrogen's been taken completely from them, i'm not to sure of the canna nutes but maybe up the N part a little especially if all leaves are goin a light green colour

how much nutes and how oftern are you administering them it might either be too much or too little of something

i usually find if your using bloom nutes they have little nitrogen in them and the plants still need it so maybe check your nutes cuz it looks like nitrogen def to me but if the leafs are curling and getting dryed outmight be too much of a certain nute

Looks and sounds like a nitrogen deficiency. Most 'cannabis' specific nutes fall short of N in their flowering nutes. Get some fish emulsion to compliment your flowering nutes....

ph is a constant 6. what product exactly would you reccomend

go to your local hydro shop and get a fertilizer rich in nitrogen or this is gunna sound crazy but you can use urine diluted with water because the urine on its own is too strong......its an excellent source of nitrogen if you dont believe me look it up