What is going on with this leaf

[arquette]

This is a GSC leaf from plant in third week of flowering. It has lots of leaves closest to the light that show the same symptoms as this leaf.
Is it cal/mag or something else ? It has been fed True Plant Science TPS 1. Supposedly this feed does not need additional cal/mag. Any help appreciated.

 

[Mañ'O'Green]

It looks like a Phosphorus deficiency. Is it hot by the leaves that have this problem. If the leaves are getting too hot the stomata are closing and the leaf cannot pull in the nutrients it needs. This would explain why it is the upper leaves when normally this would start on the bottom leaves. It would help to have pictures of the whole plant in white light.

 

[Anthropolis]

Can rule out CalMag, it looks a good bit different, and almost always starts on the lowest/oldest fan leaves. ManoGreen's got it, could be too close n hot by the light up top. What kinda lamp and how close?

 

[arquette]

Can rule out CalMag, it looks a good bit different, and almost always starts on the lowest/oldest fan leaves. ManoGreen's got it, could be too close n hot by the light up top. What kinda lamp and how close?

The light is a Marshydro TSW 2000, pulls 287 measured watts. I keep light at 20 inches above tallest flower.

It looks like a Phosphorus deficiency. Is it hot by the leaves that have this problem. If the leaves are getting too hot the stomata are closing and the leaf cannot pull in the nutrients it needs. This would explain why it is the upper leaves when normally this would start on the bottom leaves. It would help to have pictures of the whole plant in white light.

There are 3 plants in this picture. The plant closest is the problem plant.

 

[Anthropolis]

Interesting, the more Sativa ones have troubled leaves in the middle too, and the darker green Indica looks to be bleaching or having a different defficiency. The lamp should be fine, it's a powerful lamp, I have a couple, but 20 inches should be fine. Lemme check the charts and see if I can get ya some more advice too. I feel Iron defficiency in the Indica one but wanna double check and get some more input.

In any case, just don't worry too much, they'll still make decent buds on track.

 

[Anthropolis]

Hmm wait picture 3 right there does look like Calcium def, but it is presenting oddly, and doesn't match the first OP pic. this might take a group effort lol,

 

[Anthropolis]

Mkay the dark green Indica one in the back, unless it's weird lighting, might have Nitrogen or Iron def, probably Nitrogen if either of those. The very top OP pic does look like Phosphorus def but then the latest 1 and 2 pics do look like Calcium def. Hard to say for sure yet,

Here's a couple things you can do: you do not have any nute burn at all, so! you can try increasing the dosage of that nute program to 125% or 150%. Also, it's gonna be important for you yourself to know the pH of whatever they're in. Because there's a chance the nutrition is there, but the plants can't uptake it, if the pH is out of spec. For soil and coco, lots of ppl like the "Accurate 8" probe, not too costly. If it's hydro you'll have to get a decent electronic tester for the liquid.

I'll still try to round up another opinion also.

 

[Mañ'O'Green]

I agree it is not the light.

I am still thinking Phosphorus deficiency as I see it down lower in the plant where I would expect to see it.

But what is the cause: First how much are you feeding and what is your media and method?

Are you feeding enough? This is their feed chart:

and analysis

Next is what is the PH in the root zone?

Phosphorus is not easily locked out by other nutrients so we need a good look at PH.

Do you have a P-K booster if so add a 1/3 dose to your regular nutrients for the next feed. Don't get too heavy with it.
OR
You might also try adding some carbohydrates instead to feed the benies Unsulphured Black Strap Molasses works.
Normally I would think of this right away but your other plants look good - water - what is your source?

 

[arquette]

I agree it is not the light.

I am still thinking Phosphorus deficiency as I see it down lower in the plant where I would expect to see it.

But what is the cause: First how much are you feeding and what is your media and method?

Are you feeding enough? This is their feed chart:

View attachment 1192166
and analysis

View attachment 1192163

Next is what is the PH in the root zone?

View attachment 1192167

Phosphorus is not easily locked out by other nutrients so we need a good look at PH.

Do you have a P-K booster if so add a 1/3 dose to your regular nutrients for the next feed. Don't get too heavy with it.
OR
You might also try adding some carbohydrates instead to feed the benies Unsulphured Black Strap Molasses works.
Normally I would think of this right away but your other plants look good - water - what is your source?

Interestingly, all three plants were from Garden Of Green breeder pack, GSC auto's. Obviously, the one dark green plant is different.
I feed 15ml/gal every three days in well water. Each plant gets on gallon. Feed PH 5.8-6.2. The medium is Roots Organic Original .I have a cheap soil probe, one of the 3 in 1 type. If I believe the probe reading, the PH of the medium is off the scale >7. Do I need to raise medium PH ? If so, best method. Thanks.

 

[arquette]

Interestingly, all three plants were from Garden Of Green breeder pack, GSC auto's. Obviously, the one dark green plant is different.
I feed 15ml/gal every three days in well water. Each plant gets on gallon. Feed PH 5.8-6.2. The medium is Roots Organic Original .I have a cheap soil probe, one of the 3 in 1 type. If I believe the probe reading, the PH of the medium is off the scale >7. Do I need to raise medium PH ? If so, best method. Thanks.

Sorry, do I need to lower medium PH.