Yellowing leaves and darkening roots.

[bogie420]

Ok GC here goes. I have a DIY aero system in a DIY grow box 4'x2'x4' tall. I have 8 plants that I started from seed. Bagseed from some real good mid grade. The plants have been in Veg for 18 days. I am going to start flowering on sunday. The PPM is running between 500 and 550, and I am using Liquid Earth nutes. The PH level stays between 5 and 6. My nute solution runs around 78*F . To hot I am thinking.
This is my first grow. I have done lots of research, and started this project in hopes of success. Now my babies are looking a little sick, and i am getting concerned. Please check out these pics and let me know if I am in trouble, and if so any advice on how to fix it will be greatly appreciated.

Y ou can also take a look at everything i am using, and see everything i have done to this point at this thread.
http://forum.grasscity.com/absolute-...irst-grow.html

Thanks GC

[SmknVTEC]

I think your nute solution is too hot. Shoot for 72 degrees.
You seem to have some sludge there on the roots. Do you change your res at least once every two weeks? Very important. Try adding some hydrogen peroxide to the mix or an anti fungicide or something.