u got nute burn there and also bit heat stress , move ur light 3-4 inches away and just giv ur plant or plants plain water from now with a T spoon of molasses in 5ltr of water .
I use house and garden bat soil and throughout the whole grow I give my plants 3ml old timers grow just b4 I switch to flower , then about week 3-4 of flower they get 3ml old timers bloom , in between they get 90ml of molasses every other watering all these bloom boosters and other bottled feeds u buy from grow shops are just commercial sales shite , a good soil will carry ur plants all the way through the cycle with maybe a little feed just to to the soil up , remember .. ur feeding the soil ( NOT ) the plant , the soil feeds the plant