Nitrogen toxicity or heat?

[lightjelly]

Just passed Week 5 on this one Ak47 tree in coco in 3 gal pots.
Running a 400w hps in a tiny little tent so heat gets up to the 90s sometimes, however my airflow is p strong and I haven't seen any cupping/canoeing leaves.
Been watering at around 700ppm with runoff coming out to about 1000ppm(!!!)
Bud growth has been sort of slow and it looks really weird from up close.
And as you can see, waxy, dark green fan leaves, all the leaves on my bud/calyx are curled down.

So is this Nitrogen toxicity? Do you guys think I shud drop the N and only provide PK? Or just keeping the same ratio and lower the concentration?

Any help is appreciated!

 

[lightjelly]

Here is the plant.

 

[bluenoserjoe]

Good morning @lightjelly. She does look saturated with nitrogen. Not so much needed this late into flower. Back down on the nitrogen but don't stop it altogether. She is in need of higher levels of Potassium at this point in bud building. Besides that she is looking good.

 

[lightjelly]

Good morning @lightjelly. She does look saturated with nitrogen. Not so much needed this late into flower. Back down on the nitrogen but don't stop it altogether. She is in need of higher levels of Potassium at this point in bud building. Besides that she is looking good.

Good morning! Thanks for the prompt reply! Was giving about 100-100-130 ppm of NPK! However I most likely had this problem already in veg! Does cutting N by half sound good to you?

 

[bluenoserjoe]

Sure is a good place to start. Each plant will have differing needs so no one for all fit. That would be just to easy. lol

 

[lightjelly]

Sure is a good place to start. Each plant will have differing needs so no one for all fit. That would be just to easy. lol

Will do, appreciate the input! Also everyone else's advice is welcome!

 

[bobrown14]

Just passed Week 5 on this one Ak47 tree in coco in 3 gal pots.
Running a 400w hps in a tiny little tent so heat gets up to the 90s sometimes, however my airflow is p strong and I haven't seen any cupping/canoeing leaves.
Been watering at around 700ppm with runoff coming out to about 1000ppm(!!!)
Bud growth has been sort of slow and it looks really weird from up close.
And as you can see, waxy, dark green fan leaves, all the leaves on my bud/calyx are curled down.

So is this Nitrogen toxicity? Do you guys think I shud drop the N and only provide PK? Or just keeping the same ratio and lower the concentration?

Any help is appreciated!

Too much Nitrogen - don't measure run-off. Are you using bloom fertilizer or some general fertilizer??

Can shorten your lighting to 11on/13off that will speed things up in flower.

Cannabis doesn't require much Nitrogen. They more of a Ca hog. You are not that close to harvest dont go by time go my how the flowers look. You got plenty of time for the plant to burn off the N in flower. Just dont add any more.

 

[lightjelly]

Too much Nitrogen - don't measure run-off. Are you using bloom fertilizer or some general fertilizer??

Can shorten your lighting to 11on/13off that will speed things up in flower.

Cannabis doesn't require much Nitrogen. They more of a Ca hog. You are not that close to harvest dont go by time go my how the flowers look. You got plenty of time for the plant to burn off the N in flower. Just dont add any more.

Using Jacks Bloom + Monopotassium Phosphate right now! Adjusted my ratios and cut N in half while having PK remain roughly the same. I am not in a hurry so I guess staying 12/12 is fine?

Glad you mentioned Calcium, since I've added quite a bit into my nutrient water, what are you thoughts on how it affects your grow?

 

[jaybirdz]

Not much to add on the previous nutrient suggestions except to agree nitrogen may be a little high, those leaves do have a really nice dark green color indicating strong chlorophyll generation. I'd also say I think your water PH is spot on.

But your comments, "Running a 400w hps in a tiny little tent so heat gets up to the 90s sometimes, "all the leaves on my bud/calyx are curled down", tell me the light for that particular plant at its current maturity may be on the strong side. That plant may just have a slight sunburn (leaves with brown tips)

Any way to decrease the light intensity (raise its height) and tent temps temporarily? Before you do try to count how many leaves have brown tips. That way when you make changes to its diet or lighting you'll know if your going in the right direction.

 

[lightjelly]

I think I'm starting to see some early foxtailing, I think I will try running the 400w at 75% ! thank you

 

[bluter]

I think I'm starting to see some early foxtailing, I think I will try running the 400w at 75% ! thank you

the tipping is slight nute burn and is an indicator you are feeding at the right levels. it is not a reaction to the light.

 

[bobrown14]

Using Jacks Bloom + Monopotassium Phosphate right now! Adjusted my ratios and cut N in half while having PK remain roughly the same. I am not in a hurry so I guess staying 12/12 is fine?

Glad you mentioned Calcium, since I've added quite a bit into my nutrient water, what are you thoughts on how it affects your grow?

How are you cutting your N?

With the Jacks Bloom stuff you likely dont need any Monopotassium Phosphate

Jacks NPK values are: 10-30-20

Monopotassium Phosphate NPK values are : 0-52-32

Thats a lot of everything. I doubt you need any Monopotassium Phosphate along with Jacks. Are you hydro soil-less or soil??

 

[lightjelly]

How are you cutting your N?

With the Jacks Bloom stuff you likely dont need any Monopotassium Phosphate

Jacks NPK values are: 10-30-20

Monopotassium Phosphate NPK values are : 0-52-32

Thats a lot of everything. I doubt you need any Monopotassium Phosphate along with Jacks. Are you hydro soil-less or soil??

I am running coco, mostly just adjusting the ratios between those two, Been feeding at 0.8ish EC with lower N, Might be effin around but so far so good!

This might be a good read on nutrient profiles!

CannaStats - Nutrient Profiles for Cannabis

This page provides a common language spoken by all fertilizer solutions and a way to mix them for growing cannabis hydroponically. Sometimes referred to as the Lucas formula, this page explains the true origin of this well known proven formula and the project that led to its discovery. Emphasis...

www.angelfire.com

 

[lightjelly]

the tipping is slight nute burn and is an indicator you are feeding at the right levels. it is not a reaction to the light.

Hi there! The burn showed when I slightly overfeed it and the runoff reached over 2.0 ec, might've worsen the Nitrogen issue doe!