Brown spots, light green leaves?

I think ya might past the deficiency and on the mend, keep a eye on other leaves...If it happens again treat for phosphorus deficiency could be from ph issue, temp lower then 15c stressful conditions or lockout bu it's notn lockout they look really healthy other wise.... How to treat First, balance pH (Hydro: 5.8, Soil 6.0 - 6.9) or re-apply nutrient mix if necessary. Organic Solutions: • Bat Guano • Bone Meal • Crab Shell • Crab Meal Inorganic Solutions: • PK Boost Supplements • Phosphoric Acid (Soluble Phosphorus however raises pH quite a bit)