Yellow spots that are drying up my cucumber leaves.

[Joe Flores]

Hello everyone,

          I seem to be having a problem with my cucumbers in my raft bed. My system is 4 months old ,180 gallon fish tank with 50 talapia, PH 6.6 ,fully cycled. The leaves on the cucumbers on four of the plants continue to be riddled with signs of Iron deficiency ( yellow spots) and I have added a significant amount of Iron and the condition hasn't changed  all of the other plants are thriving. The grow beds that are in this garden are 30"W X 8' L X 9" D X 2 each raft and  4' X 4' X 8"D 1 each cider bed. This is my second AP system, in my first garden the cucumbers were planted in the cinder and did better can cucumbers do well in a raft bed? Look forward to reading all suggestions..Aloha

[Vlad Jovanovic]

It's highly unlikely that what you are seeing/describing is an Fe deficiency...but snap us some decent pics for some decent feedback.

[Alex Veidel]

If your plants look like they have an iron deficiency, yet you are adding lots of iron, it could be that your pH is too high. If I recall correctly an imbalanced pH causes plants to be unable to take up certain nutrients properly.