pH Fluctuation
Both of these leaves in figure 6 and figure 7
are from the same plant. It could be over fertilization,
but more likely it is due to the pH being off. Too high
or too low a pH can lock up nutrients in the form of
undisolvable salts and compounds, some of which are
actually toxic to the plants. What then happens is the
grower then tries to supplement the plants diet by
adding more fertilizers, throwing off the pH even more
and locking up even more nutrients. This type of problem
is seen more often in soil mixes, where inconsistent
mixing of the medium's components leads to "hot" spots.