Let me describe where im at. Im in week 4 of Veg running a hydro setup. Room temp 70 Night/79 Day, Humidity 50-60%, PPM 900 (500 scale), ph between 5.9-6.1, water temp 69-70. Using 450w KIND LED light and 2 T5 on the side. On the upper leaves I am having dark spots on ghe tips, and some curling upward. Also A couple stems are weak but others are strong. Im using Lotus nutrients Grow and started Cal/Mag a week ago. The grow isnt really stunted as Im getting 1-2 inces of growth per day. This is my first grow. I thought it was maybe magnesium deficiency so why I started Cal/Mag but problem persists. I also treat 2-3 times a week with Green Cleaner.