2) Growing indoor
3) watered with ph 5.5 (i use lemon juice as a ph down) every 3-4 days
4) Growing Medium : ff Happy frog
5) What stage of growth: day 43 at time of pic
nitrogen? im not sure. i included 1st pic of chemdawg for reference.. i dont think its a ph issue
your pH is way too low for soil. Soil's pH should be no lower than 6.0, that is because a lot of nutrients get locked out when pH is below 6.0 in soil, including nitrogen. try to keep your pH between 6.0-6.5 for soil.
this could be normal yellowing at this stage of flowering. I'm not sure if this is day 43 total, or day 43 for flowering, but it may just be normal yellowing associated with flowering.
