Septoria Leaves or phosphorus deficiency? HELP PLEASE!

Tonino said:

That plant that was showing the symptoms is completely healthy now and growing fast! But the other one is showing some strange signs and I think this time is closer to Septoria. Unfortunately in the last two days the humidity was around 65% and I couldn't control it since I'm using a very basic setup and don't know how to reduce the humidity, any ideas?
Anyways as I expected that some fungi are growing I cleaned the suspected leaf with mixture of baking soda, water and soap. Could someone please help me and tell me if I'm getting septoria? (There's one small yellow/brown dot behind the small leaf that I'm holding in my hand and also in the front, the one on the left.)

P.S. The white powder that u see on the leaves is the baking soda I applied.

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Tonino said:

View attachment 4164079 Okay I should have another problem! One of the new shoots got dry in less than 1 day. It should be some kind of fungi for sure!
HELP PLEASE!

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