blue blues on upper leaves

[Sunin]

So I am baffled here watching two of my plants lately.
Anthocyanins are building in new leaves- at the start I thought- phosphorus right? but phosphorus is mobile so it should be visible on lower fans too.
nope- lower fans are green and perfect. Fed them- seems to be a bit better but just a tiny bit. checked the temp- never got below 18- can't be cold.
Looked through this forum, loads of others, internet- found dude having pineapple similar but no continue there and thread from 2018.
I was growing this strain before- it never turned blue
Not that I mind this hint but I don't want to run into trouble here later so maybe any of you have any thoughts why it looks like this so I can correct it?

blue upper- hard to catch this but with bare eyes it is really beautifully blue. If I magnify I can see that where the blue pigment is -there is slightly different structure to the leaf

and behold just picture perfect below

so it can't be phospho? or can be?
thanks in advance

 

[Sunin]

close up. what seems to be here bruise grey is for the eye blue.

 

[RootFarmer]

Is it mostly starting in the middle growth? I'm asking because the leaf your showing doesn't appear to be new growth. Its a bit older. Copper deficiency? Can look like N or mag toxicity, P or K deficiency.

Unless you had a big temp drop at night, which can cause that, or a big ph swing it's probably copper. It can be a little tricky to figure out. It cam cause blue-ish and/or purple-ish leaf coloration like phosphorus deficiency and a deeper shade of green like mag toxicity. If it is actually mag toxicity then you could have some phos or copper lock up. But the shade of green I'm seeing doesn't make me think that it is the issue. If you start seeing leaf tips and edges turn a sort of bright almost neon like yellow that would lead me more in the direction of copper.

 

[Sunin]

Is it mostly starting in the middle growth? I'm asking because the leaf your showing doesn't appear to be new growth. Its a bit older. Copper deficiency? Can look like N or mag toxicity, P or K deficiency.

Unless you had a big temp drop at night, which can cause that, or a big ph swing it's probably copper. It can be a little tricky to figure out. It cam cause blue-ish and/or purple-ish leaf coloration like phosphorus deficiency and a deeper shade of green like mag toxicity. If it is actually mag toxicity then you could have some phos or copper lock up. But the shade of green I'm seeing doesn't make me think that it is the issue. If you start seeing leaf tips and edges turn a sort of bright almost neon like yellow that would lead me more in the direction of copper.

it is on upper to middle grow only. just my main is bended on side ;) that's second fan from top there.
blue is visible up- not down
in new grow it is visible only on edges- hard to see. like a glimpse
drop at night is around 4-5 degrees. It is colder lately here- July in Ireland- happens that they sit in 21-22 but I have grown before low budgeto in low temps here and never had such a blue if there's 20plus in tent
PH stable in range 6-6.5. In run off too

Copper- yes- was checking that also. I deliver copper separately in foliar so they should have enough
I do foliar from seaweed 10ml/L every 14 days to check for my friend if it helps with tolerance of LED lights. It does.
So maybe here the cat is buried and there's magnesium overdose from seaweed that blocks copper and phospho on those two particular plants?
Look of lower fans is confusing though as they look nice and green and it's hard for me to find any spots or discoloration. And between that blue green is also nice
I will keep an eye on edges
Is there any quick way to lower magnesium in soil in case? some magic dressing?
Thanks for input two heads are better than one

 

[RootFarmer]

I don't see anything that looks like Mg deficiency. It has a unique look. Phos would seem more likely given the color. Took me awhile to figure out the copper deficiency I had before. I missed it on the oldest leaves. It first really presented in mid growth. Only a crispy tip or two on the oldest leaves but that could have been anything so I discounted it. I had that blue/purple lead color a long time before any signs of leaf damage. I also assumed phos deficiency at first but noticed no change in stem color. That's when I started considering copper. A micronutrient soil drench a 2-3 days of foliar feeding hot them back on track pretty fast.

The seaweed may not provide sufficient nutrients in the case of a deficiency. I see it as more of a maintenance nutrient. Do you use Seaweed extract? I ask for two reasons. One is that extra K might throw off your nutrient balance. I suspected that more than once when I was using it. The main reason I stopped using it for foliar application is this....

 

[Sunin]

Do you use Seaweed extract? I ask for two reasons. One is that extra K might throw off your nutrient balance. I suspected that more than once when I was using it. The main reason I stopped using it for foliar application is this....

I use seaweed in this form and % first time. It's experiment on many fronts this grow. It's usually 2-4 ml/L in crops- but only veggies are checked and there's access to data- chickpea is checked the most under LEDs
Cold extract high quality- you are on the ball here
I mix root feeding with foliar feeding.
Seems that stopping foliar feed and putting seaweed extract on shelf is the way to go? Interesting