smorgasbord of problems, help needed

so my ladies seem like they're suffering..

Heres a little info...

1000 watt MH
~1 month into veg
2 Critical Kush
LST

RH - 25-30%
Temperature -77-86
(These are not things I can control, its incredibly hot where I live. I have already tried everything except AC which im not willing to buy)

DWC in 10 gallon totes about 6 gallons of actual nutrient solution
PPM 650-700 (it seems to stay there and doesnt fluctuate much)
pH 6.0-6.2

Nutes: (these measurements are per gallon)
- GH Micro and bloom (5-10ml) according to the lucas formula
- Kelp extract (5ml)
- Mad farmer NUTS (5ml) for those unfamiliar w/ this it is just pure fulvic acid)
- Dutch Master Silica (2ml)

I'm concerned about the lower leaves and the leaves closest to the stem. Some have spots, some have holes, some are dead and crispy, some are turning yellow/brown, and some are curling.

The new top growth, however, seems healthy to me... its just the lower leaves. These problems seem to b moving up VERY SLOWLY if at all but its still freakin me out.

I had a spider mite situation a while back and I heavily coated all the leaves with a neem oil/dish soap solution. The leaves were shiny but it went away. I'n not seeing any new spider mites on the leaves and I look very closely every day so I doubt they have come back.

Can anyone please tell me whats wrong with my plants? I read in another thread its normal for the lower fan leaves to die as the plant diverts its energy to new growth but I seriously doubt that is whats happening and that my plants are healthy...

One other thing the roots are brown but healthy. I'm positive its not root root because the new roots are white as snow. I think they are just stained dark from the GH Micro and Kelp extract. The top main roots however are slightly green with white bumps but I had someone tell me that its just new roots beginning to grow out and the green is from being exposed to oxygen for a while but nothing to be concerned about.

the 6th pick looks like the begining of calcium def . the rest looks like bug damage , with the exception of the third pick which also could be the aftermath of bugs but id give em a dose of bloom ferts to make shure that the third pick aint a mild phos defiency . the over head pick looks good and healthy . good luck , btw whats the ppm u running .

Looks like some badass bugs are tearing them up. Break out the Hydrogen Peroxide!

PS:I agree with pinkjackyle about calcium def. Fert them if possible.

No control on ambient temp and DWC don't mix. Id try another method if i was you, or at least buy a chiller and go RDWC.

I can tell your roots are problematic since the leaves are drooping. The plant is lacking oxygen. So if your water has sufficient DO, it must be the roots aren't healthy enough to use it. This would also be causing the necrosis spotting, as the roots aren't healthy enough to uptake nutes.

Stained roots is a myth.

RH - 25-30%
Temperature -77-86
(These are not things I can control, its incredibly hot where I live. I have already tried everything except AC which im not willing to buy)

i did not read this part , the rez needs to be about 65degF , if the rez is between 77 & 86deg thats a real prob . look into a homemade diy rez cooler , eazy to do , a cheap cooler about 50ft of tube coiled up sitting in cooler and add ice control the temp by reducing or adding feet to the coil added feet will cool more , less tubing in the coil will cool less . good luck.

I cannot see any bugs so I dont think thats the issue so going off what everyone has said I'm thinking either nutrient burn because the PPM keeps rising almost 50ppm per day or the reservoir temperature is way too hot causing nutrient lockout? Does anyone have more information? So far I've put been bottles of ice in the reservor to cool it.

It seems like nitrogen deficiency.. Does anyone agree?...