On both my first grow and now my second grow, about 5 weeks into Veg, my leaf tips starting curling down. Can anyone suggest why this may be happening? I thought on my last grow that I maybe over nuted them, so this grow I have only given them very little nutes. About half strength of earth juice grow every other watering. I am using Fox Farms Soil. My water PH is between 6.5 - 7.0. Temps around 78. Using T5's for veg and 400HPS for lower. Any suggestions? Will try and get pics if needed, but basically just the tips of the leaves point straight down.