Help! I am Desperate My Girls are Sick and 4 Weeks into Veg

HELP!!! OK here are some pictures... These are pictures of my runts and they are all yellow what might be the cause of this?




this is a picture of the girls i bought from PO notice how droopy they are can help me out with this one?



this picture is upclose of it:




This picture is runts in the front and the good ones in the back. Notice the back ones are double in size but front ones are short about 12" tall at most and super bushy they arent growing vertically but are on week 4 of veg just like the girls behind it which is ready to flip





The temp in the room during day is 76 night time its 69. I use 6" grodan, PH 5.8, PPM 1000, 4 weeks into veg for my own cuttings, CO2 at 800 right now, top feed tap water with no cal mag. This is my second run Ive already had a successful first run but this second run my own cuttings half of them are runts and the new cuttings i got from PO have been droopy but growing. Any help? Thanks! I really need to bring my girls back... So far what I've done with the PO cuttings is H2O flush 2 days then did fresh water with revive nutes (advanced) and h2o flush 2 more days then went back on regular feeding schedule but they are still droopy but growing. The runts of my own cuttings are super duper bushy and isnt taller than 12", then my other half of good girls are nice and tall and ready to flip but I cant flip it yet since the others arent ready. ANY HELP PLEASE!!! Thanks.

I've never grown at that scale, but isn't that fan blowing hot air from above your lights (of your healthy plants) downwards towards the ones that are sick?

I'm sure you have a reason for the odd (so high up, pointing down) placement of the fan, sorry for no answers.

Hello the reason for the high fans is that when the girls get big when I flip the lights get raised and they will be pointed between the lights and girls at that point during flower. I honestly think what happen is that when I put in my new babies the food was not PH'd correctly due to a non-calibrated meter. My question is does anyone know if I can get them back from this problem if the PH was off when they were put in the grodan from baby stage? thanks.

Pretty new here but I agree with you that it looks like a pH problem, especially in that 2nd and 3rd picture of the canopy. Those twisting yellow leaves seem to indicate a pH problem but again I'm just learning...also maybe consider adding cal-mag. You said you're using tap so you might not need it...have you checked for minerals in your tap? Letting sit to evaporate chlorine? Best of luck dude!

I've seen 'em recover from a pH imbalance like that (if it is one) in a couple short days, don't fret they looking good otherwise ;D