Rusty Sharpen

Hello, so i start my first grow organic. 120x120 cm tent with a 320 watt Led (Hydroca 320). 5 Gal pots Bio Bizz light mix. Nutrient bio bizz Grow/Bloom and Top Max and my PH 7.0 Week 3 of Flower and give them 1.5-2 liter water and 1 ml per liter grow bloom top max ervery 3 day. Now my leaves have issues, look rusty,sharpen brown i need some help .

Strains are Fat Banana Blue Cheese and Nothern lights from Royal seeds.

Thanks