Yellow leaves

Nitrogen is still needed in fair levels week 1-4 flowering there is still a lot of vegetative growth going on should be half bloom and half veg formula up to week 5

She is hungry for N , Nitrogen deficiency ,start her feeding also more PK too and some calmag .

Thanks guys completely forgot to update feeding chart I'm using 0.5ml per l of bio bizz bloom advanced nutrients big bud and bud candy and 1ml per l of cal mag

The plant needs different or more nutrients during flowering. Since flowering is the life goal of every plant, mobile nutrients are consumed from the leaves when there are deficiencies. Give it plenty of potassium, phosphorus, and a bit of nitrogen. But don't forget magnesium, calcium, silicon, and sulfur. Good luck!

looks definitely like a nitrogen deficiancy. light burn would usually appear on the top. since some older leaves are longer exposed to the light it can also happen from bottom, but in this case i would still say 100% nitrogen deficiancy. little hint: you can tell the difference by picking an yellow leaf. if you can pick it from the plant easy, its nitrogen defiaciany., if it is hardly attached to the stem and not easy to pick, its light burn.