Can anyone tell me what this is?

[Snurge09]

I posted a few days ago, with a possible septoria issue, I gave my ladies a flush cut away the old browning leaves on them all and I'm still getting the issue, could this be heat or light stress? All 4 ladies are the same height away from the light same feed etc any help would be appreciated as I'm failing to understand why only one plant is being affected and not the rest. Pics of all 4 ladies (yes they are all totally different but they are the same.

 

[GreenBean]

What strain is it? And are you using coco? Or is it soil?

 

[Snurge09]

The ladies are purple haze and in soil, I pH the feeds, they all get from the same feed, I've checked ppm/ec and the run off. Confusing as how one lady is suffering and the rest are not

 

[Tom Bombadil]

water source? what r u feeding?

 

[Snurge09]

Just my tap water, I have a organic fertiliser, I used this on my first grow no issues, I've attached photos of the fertiliser and my ladies after a chop

 

[BigB6]

I can't say for sure what the problem is here but I would definitely say use a better cannabis specific nutrient. The plants also look very small especially in such large pots. What breeder are you using?