today i noticed a couple of my plants have brown root tips.im growing in dwc the plamts are in week one of veg my ph is 5.8 in res and the water temp never goes above 73 usally around 69 it stays. some of the roots are in the water but the ones that have not reached the water yet are the ones with the problem. my ppm is 890 cause i used tap water changing to disstilled sunday. i didnt have any covers over the rw so some light was gettimg in i have since put covers over them. not sure if im watering enough to keep them moist i started drip one min every three hrs two days ago. looked like they were starting to droop so i stop to let them dry out a bit so the roots will grow. thanks my temps are 82-86 using co2 rh is 50-60 any help would be helpful