Brown spots on one top leaf

[gerhard2703]

Hello, yeah I have a pH and an EC meter. The values seem to be ok. I am giving them a lot of biobizz nutrition, the whole package, so I wonder if they really got a deficiency. Is it still possible? Another thought: I had turned off the fan and also the prima klima air filter at night. Maybe it was too little airflow during the night and they also got septoria?

 

[gerhard2703]

I believe it is all due to some fungus. Will get antifungals later

 

[TanzanianMagic]

I believe it is all due to some fungus. Will get antifungals later

It is most likely air circulation.

However, what are the pH and EC of the nutrient solution and the run-off.

To measure run-off, run some clear water through the medium, however only just enough to be able to measure it. The more run-off, the less reliable it gets.