Is this N def?

Hi, can you tell me if thats an Nitrogen deficiency or what is it? The pics are from 3 different plants, id guess since i treat them the same they should Show the same Problems.

Can you show a picture of the whole plant? It'll be easier to tell what's going on.

Also, what kind if soil, and what are you feeding?

Just from those pics... I wouldn't rule out nitrogen deficiency, but there are other possibilities.

For me - it's Potassium. The other leaves are dark green , kinda rules out Nitrogen. You can also see it's Potassium by the way it starts.
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I will say that it is NOT a Nitrogen deficiency. That would show in multiple leaves and the plant would not be as dark green overall. Best of luck on your grow.

Thx for your answers. Generally id say those are like the only leaves on those plants that Show something like that...but I want to counteract before it spreads. Soil is biobizz lightmix/allmix and nutes biobizz grow, im feeding like <half the suggested dose. Watering 1-2 times a week.

Yeah i dont think thats a N def, (from my previous outdoor exp)
But Its still a beautiful grow.

the main culprit seems to be phosphorous to me. the leaves and red stems are a dead give away.
as for deficiencies, i definitely see potassium, mag, and calcium.

your problems seems to stem from waterlogged roots or cold temps in your room.

Too much Phosphorus levels affect plant growth by suppressing the uptake of: Iron, potassium and Zinc, potentially causing deficiency symptoms of these nutrients to occur def in plants. A Zinc deficiency is most common under excessive phosphorus conditions,
As well as causing other nutrients to have absorption troubles like zinc and copper. Phosphorus fluctuates when concentrated and combined with calcium

looks like calcium deficiency to me. get some cal/mag and your good to go. GL

Can you rule one out mag or cal? because i have espom salt...that i could use for mag, right?

your problems seems to stem from waterlogged roots or cold temps in your room

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but that could be true too, if the roots were waterlogged, would the plants not be more droopy? but indeed its pretty cold 18-20°C...im building a 320W DIY led Panel, i had to salvage my old one for that, so now there is like only 35W of led and they stopped like growing at all it feels like (I bend the "heads" down, usually the next day or hours later the head was again "looking" at the light, now it doesnt in days)...and the 35W panel produces like no heat at all, before that i had like 24-25°C in there with 130W.

Is this plant a clone?

Is this plant a clone?

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Those pics Show 3 different plants, like the only leaf affected on each. 4x bagseed, 1x Skunk#1 all from seed, one plant i topped and made a clone, but its hidden below the other plants in the pic of my 2nd post.