Help Fast Sick Plants

Anybody please help, I am 3 days into 12/12 two weeks ago my plants lower leaves started to yellow and get brown spoted. Before that they were very green and lush.
Soil ph 6.5
bottled water ph 6.7
temp 78
nutes 7/4/4 two times a week, but i have given them no nutes for a week i thought it might be nute burn. they were not getting any worse but today all the leaves are sagging and they are looking a little worse. The yellowing and brown spots have started on the new growth at the top now.
Can anybody help with some advice. Thanks
peace

Full grow room pics.

They are in soil, and you are feeding them twice a week? They can find food in the soil, y'know. So I would say to stop feeding them, and try some plain water for a week or 2.

HTH

how do i know if they are to far gone to save? It looks to me like there are 3 female. Should i try to clone them and start over?
peace

clone them and then let them finish. do not use those nutes for flowering; that's a lot of nitrogen.

flush the soil. Just put them in your bathtub and run like 5 gallons of water through each one. PH'ed and purified or distilled water of course. Then let them have just plain water for the next week or so.

Don't clone them unless you want clones. I usually don't take cuttings after the switch to 12/12. Don't want to waste the healing energy. You'll be surprised, they will bounce back. I would flush like I said and use NutriGrow for 2 days. No longer than that since they are in flower. They are going to turn yellow early and you'll lose lots of leaves, but they will be just fine.

could b a no. of things mybe dont water there 4 a day or 2 after they r flushed move the light up a lil an id spray them with some epson salts could b a mg defection they,ll b ok ive seen worse come back

I had mag defficiency and it made all leaves dark green on outside and very light in middle. Make sure you nutes have micronutes in them. If thats not it and those leaves gettin enough light i would try and see if it could be a disease. Make sure it not spreading to other leaves. If it does slice those off quick. good luck man

if its not a mg defencey its bad ozone id say mg only 4 the droping leafs 1 of my plants r recovering still from mg def, another thing i learnt from mistakes if the soils 2 compressed can go simialer 2 that 2