Hello guys, im a new grower. this is my 3rd grow and i have never encounter a deficiency symptom like this (milky brown spots on leaves and some of it on the tips). it is currently finishing week 4 and i've had only given her nutes two times (1/4 strength & 1/2 strength). every watering were PH adjusted around 6.5-6.7 and this plant is grown in a cheap commercial potting mix + perlite, using a cheap 100w QB from alibaba (15 inch distance). help are appreciated. happy weekend