What is the cause of this?

[dougied86]

Is this a nitrogen toxicity? Top leave curling down. And bottom older fan leaves starting to have brown rust spots? It's in coco, water ph and soil ph good.

 

[MrGreenfinga]

Is this a nitrogen toxicity? Top leave curling down. And bottom older fan leaves starting to have brown rust spots? It's in coco, water ph and soil ph good.

I am not a coco grower but this definitely looks like some buildup are you checking runoff EC/Ppms?

 

[dougied86]

I am not a coco grower but this definitely looks like some buildup are you checking runoff EC/Ppms?

My meter broke about 3 months ago. Sadly can't check ppm. If you know of a good cheap one please let me know.

 

[MrGreenfinga]

My meter broke about 3 months ago. Sadly can't check ppm. If you know of a good cheap one please let me know.

Im not in the states and about anything will work just fine
Just give it less nitrogen its in flower too what have you given it so far?

 

[Mothman]

Maybe it’s the photo angle, but it looks like the top may be a little too close to the lamp.

 

[dougied86]

Same feed as this plant. Yes I know there about 4 weeks split in growth. The light is about a foot away from top of plant. I use jack nutes. If you look at the original Pic of the top of the plant you can see the top leaves on the lower cola still have a couple clawed leaves and way far from light. Not wind or light burn. Only thing I can think of is I feed wrong note. I have in same tent some 6 weeks flower and other just starting. Most autoflowers.

 

[dougied86]

Here are those lower leaves showing same sign. And far from light.