NL Micro Coco Hempy. Inter vein yellowing

Hi All.

So I'm having a bit of issues with my grow I was wondering if anyone can help out.
Brief overview of grow:
PC case
Coco perlite hempy 1L
Northen Lights bag seed.
75 Days from seed
Approx 30 days into flower.
60W Led 4000k
Temps are around 26-30 degrees C
Nutes is Nutriplex 3 part. Same npk as GH Flora.
Feeding twice a day till 30% run off @ 800ppm and 5.5 to 6.5 ph.
I was previously using 5-5-5 but have switched to 0-6-9.

I'm getting inter vein yellowing. I thought it might be a ph issue at first so I flushed the pot with PHd water at 6.0 and flushed till ppms dropped till about 800ppm and ph came out at 6.5
No sure if this is the correct way to flush but panicked when I saw the ppm run off was 1300ppm at first.

I'm still getting the issue. I water with tap water that has an ec of around 115ppm.

Here are some pics to help.

i think both ph and ppm are a little high. you might have had some salt lockout as well. try to keep ppm around 800 with 20% runoff every time. ph 5.8-6.0. I also run a GH equivelant brand at 0-6-9 plus 3 of calmag (botanicare). My tap water is 10ppm only

I'm not using cal mag as I read if your tap ppm is around 150ppm you can get away with out it.
How can I fix the lock out issue?

if you flush through with 1/2 strength -400ppm solution at 1-2 times soil volume, you should do it. then back to 800ppm at next watering with 20% runoff every time.

Q9550 said:

I'm not using cal mag as I read if your tap ppm is around 150ppm you can get away with out it.
How can I fix the lock out issue?

Click to expand...

Are you sure?
What you are seeing could actually be severe Mg deficiency.

Light intensity issue?

Chunky Stool said:

Are you sure?
What you are seeing could actually be severe Mg deficiency.

Click to expand...

This could be, coco is known to need more Ca and Mg. you might want to add a small bit like 2-3ml/gallon to your feeds.

Mg is at the center of the chlorophyll molecule, so it's common for severe deficiencies to show up as necrosis/yellowing. Purple leaf stems are also a sign that your plants want more Mg. It is a very common deficiency in otherwise healthy gardens.
If I were you, I'd try an epsom foliar and see what happens.

Thanks all for the replies.
I will try the epsom foliar feed today when I get home and see if that helps.
I thought it could be light intensity so I turned 1 of them off so now running 40w. Couldn't raise or lower so off was the only option.

Only managed to get the epsom salts today. Foailar fed at 1tsp/L phd to 5.6
Hoping to see some improvement.