undergrowth dieing

I dont have any pics my camera isn't working so i will try to describe my problem the best i can.

First, the undergrowth on my mothers and crop are dieing/been dead.

My flowering room is:
-1400ppm CO2
-7th week flowering
-humidity 45%
-temp 90-95 F
-Advanced nuts 1300ppm 0:1:1 ratio
-PH 5.7
-600 watt lamps
-Airoponic/drip system setup
-Clay balls grow medium
-Watering 15 on 15 off
-resivor temps avg 75-80 deg F (i know thats not good but chiller has been acting up and due for replacment)

veg room:
I have a 7 month old mother and 4, 3 month old mothers and again all the under growth is dieing almost like its creeping up the plant
-soil
-400 watt/125w led
-1:1:1 ratio Advanced nut @600ppm
-PH 6.7
-humidity 50-60%
-temp 75-85 F
-Watered about every other day

I had some major temp and ph problems with this crop flowering now but the mothers have always had good temp humidity ph nuts etc. The undergrowth death seems to be creeping up the mothers. The top leaves, on mothers, look green/ healthy and no noticeable problems. I cant figure it out. please help.

its your 7th week flowering all the fan leaves die off its coming toward the end of her life cycle....

cbtwohundread said:

its your 7th week flowering all the fan leaves die off its coming toward the end of her life cycle....

Click to expand...

Ill try to be more clear, ALL of my under growth is dieing. Buds, fan leaves, water leaves. The same thing is happenning to my mothers but worse and they are vegging not flowering. The tops of all the plants look good, even the fan leaves. Its the bottom of all my plants that are dieing. This is my 6th or 7th grow and has never happened to this extent.

Can anyone help plz??? It seems this problem might be deadly to my mothers.

The other thing i noticed is that it seems all the death is occurring in the places where there is very minimal light shinning on them if any at all, ie the growth at the bottom of the plants.

Plz help any ideas are appreciated.