Please Help Solve New Problem,yellow Leaf Tips Not Burning

[gordonian]

So I have a some grape kush that is in week 3 of flower. All the leaves in the upper third of the plant are yellowing starting at the leaf tip working its way back. . I am in coco 2 gallon pots feeding 1500ml 3 times a day with roughly 20% runoff. room is 78 degrees with 62% RH. nights are running about 5 degrees cooler. Mills nutrients ph to 5.85 E.C. 1.6. Lights are 4 feet off canopy. I did a slurry test and P.H. was 5.8, but with a blue lab soil ph probe the pots were reading 5.3-5.7., not sure which is accurate. Any ideas what it might be?

 

[Two.Bears]

could the plants be root bound? 2 gallon pots are small

So I have a some grape kush that is in week 3 of flower. All the leaves in the upper third of the plant are yellowing starting at the leaf tip working its way back. . I am in coco 2 gallon pots feeding 1500ml 3 times a day with roughly 20% runoff. room is 78 degrees with 62% RH. nights are running about 5 degrees cooler. Mills nutrients ph to 5.85 E.C. 1.6. Lights are 4 feet off canopy. I did a slurry test and P.H. was 5.8, but with a blue lab soil ph probe the pots were reading 5.3-5.7., not sure which is accurate. Any ideas what it might be?
View attachment 760190

 

[Dunge]

I'd spray it with calcium chloride foliar.
see tomato end rot spray.
If it improves, solved.

 

[Thejoeybrown]

could the plants be root bound? 2 gallon pots are small

He’s in Coco. 2 gal is more than enough to grow a tree. I run 1/2 gal pots the whole way thru in straight coco

 

[Two.Bears]

the traditional wisdom

3 gallons fine for auto flowers.
5 gallon fine for most indica
7 gallon or larger for Sativa.

to me i think she needs a new pair of shoes.

 

[Thejoeybrown]

the traditional wisdom

3 gallons fine for auto flowers.
5 gallon fine for most indica
7 gallon or larger for Sativa.

to me i think she needs a new pair of shoes.

That’s for soil. Holds way less oxygen.

Coco is a different animal. You don’t start seeing the potential of coco until those roots fill that pot out the whole way.

 

[Thejoeybrown]

Transplanting would do only harm and no good IMO. You look to be about 3 weeks into flower and the next weeks are most important. Why disturb the rootzone. Trust me 2 gal in coco you can grow as big a plant as you can fit without getting root-bound

You are feeding 3x a day so it shouldn’t be getting dried out.

Personally I think everything your doing feed wise sounds good so shouldn’t be locking it any nutrients. .
Are the stems purplimg?
It looks like could be mag or potassium.

But that would most likely mean a lockout because all those should be enough in your base. What’s your runoff ppm?

 

[stonestacker]

How long have you been growing? Have you grown in coco before? are you supplementing CA?
In my grow when my plants start to yellow like that I up my CA. Through trial and eror thats what works for me.

 

[Two.Bears]

I Understand that Coco is different from soil but those ladies still need room for their roots.

That’s for soil. Holds way less oxygen.

Coco is a different animal. You don’t start seeing the potential of coco until those roots fill that pot out the whole way.

 

[Rootbound]

How long have you been growing? Have you grown in coco before? are you supplementing CA?
In my grow when my plants start to yellow like that I up my CA. Through trial and eror thats what works for me.

Same here. Especially when the symptoms are at the top of plant. Low calcium can cause other issues also.

 

[stonestacker]

I'd spray it with calcium chloride foliar.
see tomato end rot spray.
If it improves, solved.

This will give you the fastest response.

 

[gordonian]

Transplanting would do only harm and no good IMO. You look to be about 3 weeks into flower and the next weeks are most important. Why disturb the rootzone. Trust me 2 gal in coco you can grow as big a plant as you can fit without getting root-bound

You are feeding 3x a day so it shouldn’t be getting dried out.

Personally I think everything your doing feed wise sounds good so shouldn’t be locking it any nutrients. .
Are the stems purplimg?
It looks like could be mag or potassium.

But that would most likely mean a lockout because all those should be enough in your base. What’s your runoff ppm?

The only stem purpling is on some leaves, and my runoff E.C. is between .8 and 1.1

 

[gordonian]

How long have you been growing? Have you grown in coco before? are you supplementing CA?
In my grow when my plants start to yellow like that I up my CA. Through trial and eror thats what works for me.

Been growing on and off for a few years. I am fairly new to coco I was in rock wool prior to coco. Im going to try upping my CA on a couple of plant and see what it does
thanks