Help out a first time grower, leave tips curling up and turning brown on edges

Ok so this is my first grow and ill give you a rundown on my setup...

Running DWC with lucas formula at about 600 ppm in RO water
Ph is adjusted to 5.8 every morning and rises to about 6.1 by the time I adjust it again
600 watt Metal Halide light with air cooled hood 26 inches above the canopy
Temp is consistently between 78-81 F
Humidity is consistently between 49-51 percent

The plants were transfered from soil 8 days ago and the roots are starting to take off like crazy, and are pearly white.

Strains are Cinex (Cinderella 99 x OG Kush) and Jack Herer

I probably forgot something important so if anything else would help with diagnosing the problem Ill post that info as needed. Thanks again everyone.

when you see the leaf tips and leaf edges turn brown like that it means you have overfed. that is nute burn.

ok thanks for the reply, ill try toning down the nutes a bit. Although the new growth is looking much much healthier. So I think im going to let them be for about 2 or 3 more days and see what happens. thanks again for the help