flowering problem help

hi guys i got a 2x2 tent with 9 plants (jack herrer) that vegged for 2 weeks . I am using coco, canna nuts and now(beginning of week 4) i changed to 400w hps .I got normal temps(26 C) into my tent but high humidity (80%) . My plants at the beginning of this week have started to shown pistils ( very delayed) and 4 of them seems to be stressed (yellowish colour) and i dont know the reason. Is an explanation ,the fact that I got the seeds from a hermie jack herrer and the fact that i was using the same bottles of fertilizers for 2 years?

Any help?

Could be a number of things. How's the temps... do you have some air flow going...?

i got 1 inline fan ,1 exhaust and 2 oscillating fans and only 3 of my plants are stressed. Check out these fotos. Its the first time that my coco grow is delayed and fucked up and i dont know the reason.I am thinking of eather the lifetime of the fertilizers or the fact that i used a new coco medium from a local store are the reasons for the stress...

I may be wrong but it kinda looks like the start of an iron deficiency.

I am thinking of revegging the 3 stressed plants instead of throwing them away and later i can put them in flowering again. What do you think?

Have you tried flushing with a gallon of distilled water and checking the runoff ppms? Have you checked the coco you bought for salt residue?

Leafs curling down can signify quite a bit of problems, most commonly over-watering/drowning or a variety of nute lockout. U also mentioned high humidity. I would let the plants dry out, then soak in ph balanced distilled water just to flush any salts that may have accumulated out of the system. I would not add nutes, as that may exacerbate the problem.