Hey guys my name is Corey and this is my first grow. I use FoxFarm nutrients, Mammoth P, Recharge, in a 3×3 with HLG 120, humidity is 46 and 80 degrees. Every thing was running great until a week ago when I noticed some yellowing on the tips of the top and mid leaves. At first I thought nutrient burn so I stopped using my nutrients and just feed it water the past 3 waterings. I looked online and it might be a copper deficiency (yellow leaves and curling up tips) It seams it’s getting a little worse each day. Now I’m thinking it’s lockout so I flushed it with RO water pH to 6.5. The run off pH was 5.9-6.0. Now I’m waiting to see what happens. How do I know which one it is? Should I check my ppm? Please help and thank you.