Looks like nitrogen deficiency, and possibly Mg deficiency, The plant leaves normally turn yellow when u get to the end of flowering because of the nitrogen uptake to the buds, but then u have burns in the leaves that are cause from nutrient lock up, that happens when u have an uneven amount of nutes, like too much Ca and not enough Mg, this happened to me a while back, i flushed the nutes and roots then made sure i had the right amount of everything. Ph can also be a huge problem because the roots will absorb different minerals at different Ph, so u can start your ph low at 5.3 and let it rise to 5.9 and then pull it back down again, the wonders of HYDRO!!