Yellowing between veins and on edges of top leaves

[Forage]

Some of my upper fan leaves are getting this. Coco, almost 40 days since the flip to 12/12. Feed every watering, 20% runoff.

At the flip I was (from the labels):

N-150
P2O5-50
K2O-100
C-120(high, kind of hard to fix with what I have on hand, for now)
Mg-20(Low, because I had a bad info on Mg% in epsom salts. I'm putting 2 grams per 10 liters of feed).

I've increased all levels by a third over the last 5 weeks, runoff is consistently 0.2EC below water in.

pH is about 6 in, 6 out. I'm using drops and my water isn't totally clear so the reading can be murky but it seems normal.

 

[Tracker]

View attachment 4931229

Some of my upper fan leaves are getting this. Coco, almost 40 days since the flip to 12/12. Feed every watering, 20% runoff.

At the flip I was (from the labels):

N-150
P2O5-50
K2O-100
C-120(high, kind of hard to fix with what I have on hand, for now)
Mg-20(Low, because I had a bad info on Mg% in epsom salts. I'm putting 2 grams per 10 liters of feed).

I've increased all levels by a third over the last 5 weeks, runoff is consistently 0.2EC below water in.

pH is about 6 in, 6 out. I'm using drops and my water isn't totally clear so the reading can be murky but it seems normal.

What are your temps and humidity?

 

[Forage]

Humidity has been around 50-60%.

Heat just spiked so we're 24-29C/75-84F but until a few days ago more like 20-25c/68-77F.

Both of my indicas have this, one has for weeks, the other one just started showing it.

 

[Leeski]

What size pot ? Looks tiny from pics

 

[Forage]

What size pot ? Looks tiny from pics

The pots are 15 liter. There's about 7.5kg/16lb of coco in each pot when fully saturated.

I would say that you're right, and the pots are a bit undersized. I flipped late and they got bigger than planned, and I didn't have enough coco to fill the pots all the way in the first place. But they might look smaller because the height of the plants makes the pot further away from the camera.

 

[curious2garden]

View attachment 4931229

Some of my upper fan leaves are getting this. Coco, almost 40 days since the flip to 12/12. Feed every watering, 20% runoff.

At the flip I was (from the labels):

N-150
P2O5-50
K2O-100
C-120(high, kind of hard to fix with what I have on hand, for now)
Mg-20(Low, because I had a bad info on Mg% in epsom salts. I'm putting 2 grams per 10 liters of feed).

I've increased all levels by a third over the last 5 weeks, runoff is consistently 0.2EC below water in.

pH is about 6 in, 6 out. I'm using drops and my water isn't totally clear so the reading can be murky but it seems normal.

Interveinal chlorosis is classic Mg deficiency and you're right about the time it would show too. You need more Mg. Those leaves won't get better but things will stop getting worse. Best of luck.

 

[curious2garden]

The pots are 15 liter. There's about 7.5kg/16lb of coco in each pot when fully saturated.

I would say that you're right, and the pots are a bit undersized. I flipped late and they got bigger than planned, and I didn't have enough coco to fill the pots all the way in the first place. But they might look smaller because the height of the plants makes the pot further away from the camera.

You're in hydro. I finish in 2 gallon pots and have finished healthy 6 ft plants. The size of your pot just affects how quickly your pots dry out and how often you need to feed/water up to a point. I haven't reached that point myself though.

 

[Forage]

Interveinal chlorosis is classic Mg deficiency and you're right about the time it would show too. You need more Mg. Those leaves won't get better but things will stop getting worse. Best of luck.

Thanks for that. I'll bump up the epsom salts a bit and see how things go.

I thought I had noticed a bump to my yield when I switched to bigger pots, but there's too much variability to my grows to draw any real conclusions.