Deficiency or nute burn?

Northbar

420 Member
Good morning all,

I could use a bit of help. Plant in question is an auto approx 15in tall in flower.

- Light is hlg320 about 20in from tops.
- soil fox farm happy tree frog
- water sourced from natural spring. 6.5 ph
- currently feeding megacrop at 1g/gal

I know autos can be finicky with nutes so I kept the dose low for her size. I flushed her about 2 weeks ago which she loved but is still showing leaf tip burn with other discolorations.

Any help on my next move would be appreciated.

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Highya! Welcome to :420:

Most definitely deficiency.
What you are seeing is mostly Potassium (K) def. 1g/gal MC is not nearly enough for a plant that size. You should probably be using at least 3g/gal - even with FFHF.

Happy gardening!
:surf:
 
Thank you very much. I’ll boost the MC dosage on her next feeding
 
This is a very important lesson and I am glad you are learning this early in your gardening.

For future reference, brown tips and edges in only lower to middle leaves indicates K def.

Brown tips in upper leaves indicates that nutrient concentration is higher in the medium than in the roots - this results in water being pulled out of the plant (through osmotic pressure) to dilute the higher concentration - and this causes the “nute burn”.

It is always better to provide a slightly lower concentration of nutrients and deal with a minor deficiency than to have to address excess/toxicity.

The existing leaf damage will not be repaired, but you will see that damage does not progress upward once you provide enough nutrients. This is what to watch for as you address the deficiency.
 
She was dark green and 6” tall for 2 1/2 months before she started stretching to 15” in a 2gal pot. This is my first plant without nitrogen OD. Its a balancing act I dont quite have down.

This grow started early July.
 
This is a very important lesson and I am glad you are learning this early in your gardening.

For future reference, brown tips and edges in only lower to middle leaves indicates K def.

Brown tips in upper leaves indicates that nutrient concentration is higher in the medium than in the roots - this results in water being pulled out of the plant (through osmotic pressure) to dilute the higher concentration - and this causes the “nute burn”.

It is always better to provide a slightly lower concentration of nutrients and deal with a minor deficiency than to have to address excess/toxicity.

The existing leaf damage will not be repaired, but you will see that damage does not progress upward once you provide enough nutrients. This is what to watch for as you address the deficiency.
Ok so my brown leaf tips are upper and lower. Basically every leaf tip throughout the plant has this tip burn brown and up curl.
So this indicates an excess/toxicity correct? So I need to reduce MC further? 1/2g/gal?

One of the picture views was from the top of the plant looking down. Just indicating that it is throughout the plant

I assumed nute burn cause she was so small. She went from 6” to 15” and bushy in a week after stalling for 2 months at MC 1g/ gal. I almost pulled her. During late stretch i added 1/2g/g sweet candy to the 1g/gal. The burn was progressing so I flushed and went back to MC 1g/gal and recharge. She was super happy about the flush. However the browning still slowly progresses

What would you do at this point? I been trying to figure this out for months.
 
also, you might want to re-read the GLN instructions for using MC... any leaf damage or change in color should cause you to adjust your dosage. This has been going on for a while now... I am curious why you have been staying at 1g/gallon?
She was 6” for 2 1/2 months. Sudden stretch followed so trying to catch up to her feeding need and dial in. Leaf color is primary concern on GLN so I upped my dose to 2g/gal and see if that helps stop the burn deficiency
I also raised the light to 25” since the upper half of her is a bit lighter than her lower half.
 
You are confusing starvation for burn... it is a common mistake because when the plant needs to cannibalize leaves for their nutrient value, it does look like a burn. Due to the extremely small size for the age of this plant, I would say that you are also watering incorrectly. Please read both of my how to water articles for further insights as to this problem.
 
You are confusing starvation for burn... it is a common mistake because when the plant needs to cannibalize leaves for their nutrient value, it does look like a burn. Due to the extremely small size for the age of this plant, I would say that you are also watering incorrectly. Please read both of my how to water articles for further insights as to this problem.
You’re right I had it flipped. I lost track of the gln rules and needed the pros here to help confirm my direction. And I won’t drown her on the way back to health.
 
Ok so my brown leaf tips are upper and lower. Basically every leaf tip throughout the plant has this tip burn brown and up curl.
She is looking all over for the nutrients she needs. If it was only the upper leaf tips, that would indicate excess.
 
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