Do I feed too little, or wrong PH value?

To little to late, I would do nothing at this state as harvest on that plant is less than two weeks away i would guess. Or give them final nuts following instructions. Its decent and the quality looks good, just think the plant could have yelded better with more nuts, proberly just by following instructions.

Hi, how are you??? I usually feed the plants a little less than the label on the back. For instance, if it says 2.5 ml, i give them 1.5 which You did. The second feed, i do 2ml and from there on i give them the Regular amount indicated by manufacturer. your plants are also flowering so some the leaves are going to turn yellow and brown as they use all the energy to create big budz. For flowering used the same principle for feeding. And donT forget to stop the nutrients a few weeks before harvest. Happy harvest and high fun!!!!!!