Why are my leaves Turning yellow? >.<

https://www.rollitup.org/blogs/blog14176-thread-cannabis-nutrient-deficiencies.html

this is a guide to deficiency I posted in my journal stolen from billy4479.
Most the time it is lack of N but take a look at the guide.

Thank you, that was really helpful =]

That girl is simply hungry and needs more N in her diet. Some plants whether different strains or phenos will require different levels of nutes to maintain their health. Don't be afraid to bump up the nutes a bit and then wait a several days and see how she reacted, if still a bit little in color add a bit more to the diet until she looks darker in color.