sigh
ok its not easy to suss out , when someone over feeds or under feeds the plants starts fucking the leaves up , the only thing you can do is stop what your doing and aim for a proper feeding schedule after a flush , once a leaf starts to show signs of stress nothing will recover it , you therefore rely on no more turning to crap and decent new growth
so keeping it simple
ionic grow in veg , clones feed slightly lower than the mother they come off ( 800 ppm ) , seed grown then chill until 3 weeks or more old and then 500 ppm
vitalink in flower then run upto 1200-1400 , 1600 is the top limit if its friggin huge , add a booster 4 weeks before cutting
this is all thats needed , of course shops will sell you no end of strange concoctions that will promise to do no end of things but the reality it the plants a weed and if you treat it right it will reward in kind , right is therefore not having its roots swilling around in a fuckin awful chemical soup that the plant has no chance whatsoever of absorbing , adding food is easy if you lightly feed but taking away is a real twat to manage and no matter how many times you flush the roots will need time to recover
so there you go , a general answer , cant offer any more seeing how you havnt said feeding , lighting , plant stage , full picture , progressive or immediate , p/h levels etc etc