Deficiency or excess of nutrient?

Like the boys said, its a mag deficiency, goodluck :)

Hey growmie I work with biobizz a longer time , raise bio grow to 2ml/l alga mic to 3ml bio bio heaven 2ml/l CalMag can stay same but use it by the next and every watering. Use Alga mic as spray for the leaves until buds are visable . It will help not to spred the deficiency from CalMag. You must feed every watering buddy Get to my diaries and luck at purple punch or green crack . Follow my schedule week for week , i promise you want have no problems , but if you let it stay so low then it start to show issues and you don't need now in flower. You can't fix them anymore , so handle fast ! Wish you good luck buddy 😎