COCO COIR what is this?

[BapusO]

I'm already treating my plants with neem oil solution for mites, now this is going on. First the tips and edges turn brown/ black and dry, eventually turning the entire leaf black and crumbly. The black looks like mold but a close look shows no fuzzyness like mold. Can you tell by this picture what it might be?

 

[DW2]

Howdy BapusO, What are the growing conditions (nutrient levels, temperatures, pH, and type of grow)? The leaf damage could be from a lot of different (or combination of) conditions.

 

[BapusO]

Yeah, I know all that and you're right. I've ruled out most all of the normal conditions that I can control, nutes, watering, lights,etc. I have a coco grow in a grow room that I can't keep cool enough. It's constantly too hot in there but can't afford air conditioning, so I use fans and an exhaust ventilator as best can. Other than the heat it's a good grow (I grow good pot) except for something new going wrong with every grow I start. I was just hoping someone might know what just starts turning leafs black and crumbling.

 

[Guest]

have u calibrated your pen lately..looks like a ph prob.... you have experience so idk just a thought brother.