Mr.Wakenbake said:
Any type of stress can negatively affect your yeild in the end. Especially over Nitrification which has happened here.
The leaves tell all ann... and im telling you it isnt fungal, it's Nutrient burn.
Brown necrotic patches, affecting the whole plant, clawed leaf ends, leaves cupping downward from the center vein all signs of nutrient burn. flush em.
the leaves tell it all? Where do you see a rams horn claw? Where do you see yellow burn marks creeping in?
Nute burns always start from the tip and work there way in, leaving actual tell tale burn marks. I can tell you that this is not over nitrification, this is root damage that too me looks to be caused by your ph or a fungi. If you have a high tds then your ph would read as low because of the acidity of the ph of the minerals
Nute burns do not affect the entire plant this way, they affect whatever is activly growing, firstly the new growth, the fact is that you could burn your plants serverly, and only see the effects on 1 set of leaves, if you flushed your plants properly.
Leaves cupping is a sign of a deficiency not nute burn... Magnesium to be exact, which is also displayed on the bottom set of leaves by the edges yellowing then browning, but infact the browning on the bottom edges was more then likely caused by whatever problem that caused the entire top leaf to discolor and die.
Brown necrotic patches are once again not caused by overfeeding, they are caused by fungi, ph or rarely a phosphorus deficiency which often gets mistaken for a fungal problem.
I have included a picture of a classic nute burn. One just starting and another very bad which did not happen over night, more like over the life of that leaf.
Also please notice how in the picture with the badly burned leaf, the other leaves from the same plant are totally fine, even the growth tips.
You may want to look into Fusarium, Phytophthora and Pythium, which all cause root rot and occur naturally in soil.