Northern Lights Phosphorus Deficency?

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Eastwind

Eastwind

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Hello growers. I'm in a soil grow of Northern Lights. My Ph is 6.5. Daytime 60-70s at 49rh. Period: into the 4th week of flower. Lighting: Led & CFL, total 555watts. Nutes: Dyna Gro Bloom, Superthrive, Molasses.

On these symptoms, it is not all of them on every plant, but here they are: Leaf color: lower fans, yellow with some reddish and purple areas. Leaf symptoms: Lower older growth, red stems, old leaves drop off, slow growth (some), some (on one) twisting/abnormal leaf growth. Plant symptoms: red or purple stems, slow growth, one - stretch in buds, not fattening.

Possible errors I've made: improper watering ( without having run off ), not letting the plant dry out enough before adding more water, and there was a temp fall a few nights...into the low 40s/maybe 38-39.

All 5 plants have LST. 1 is a good green with fat buds, 1 is a good green, stretchy, thin buds, 3 are runts, that never got a real dark green, are short, but for their size the bud look good & fat, their stems are purplish.

Since my Ph seems good, I was going to do a flush with 10-20% runoff (plane water or with a reg dose of Bloom 3-12-6 ?) to see if that sets it right. Some say the cold nights may have done this and its not due to low P... I have been using Bloom in my watering (water was mixed - some filtered store bought, some from my tap). By the look of the white hairs on the buds and the Tri's ( some red/brown hairs and clear Tri's ) I have maybe 3-4 weeks to harvest. Photos: 1 thin bud, 2 off color leaves, 3 bud top, 4 good plant. Any suggestions are appreciated.
 
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GT21

GT21

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Hello growers. I'm in a soil grow of Northern Lights. My Ph is 6.5. Daytime 60-70s at 49rh. Period: into the 4th week of flower. Lighting: Led & CFL, total 555watts. Nutes: Dyna Gro Bloom, Superthrive, Molasses.

On these symptoms, it is not all of them on every plant, but here they are: Leaf color: lower fans, yellow with some reddish and purple areas. Leaf symptoms: Lower older growth, red stems, old leaves drop off, slow growth (some), some (on one) twisting/abnormal leaf growth. Plant symptoms: red or purple stems, slow growth, one one - stretch in buds, not fattening.

Possible errors I've made: improper watering ( without having run off ), not letting the plant dry out enough before adding more water, and there was a temp fall a few nights...into the low 40s/maybe 38-39.

All 5 plants have LST. 1 is a good green with fat buds, 1 is a good green, stretchy, thin buds, 3 are runts, that never got a real dark green, are short, but for their size the bud look good & fat, their stems are purplish.

Since my Ph seems good, I was going to do a flush (plane water or with a reg dose of Bloom 3-12-6 ?) to see if that sets it right. Some say the cold nights may have done this and its not due to low P... I have been using Bloom in my watering (water was mixed - some filtered store bought, some from my tap). By the look of the white hairs on the buds and the Tri's ( some red/brown hairs and clear Tri's ) I have maybe 3-4 weeks to harvest. Photos: 1 thin bud, 2 off color leaves, 3 bud top, 4 good plant. Any suggestions are appreciated.
There are 3 usual scenarios....
1 is a phos def
2 your flower nutes have made your ph swing over time and youre locking phos. Which means theres plenty of phos.. your plant just cant get to it right now.
3 cold weather lowers the conductivity of roots
 
Eastwind

Eastwind

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There are 3 usual scenarios....
1 is a phos def
2 your flower nutes have made your ph swing over time and youre locking phos. Which means theres plenty of phos.. your plant just cant get to it right now.
3 cold weather lowers the conductivity of roots

So maybe a plane water flush at the next feeding time? See how things respond after that? I may have gone a little heavy on the feedings a few times...that combined with the cold might be the answer. So, other than a flush, just let it be ( and keep the night temps up)?
 
GT21

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So maybe a plane water flush at the next feeding time? See how things respond after that? I may have gone a little heavy on the feedings a few times...that combined with the cold might be the answer. So, other than a flush, just let it be ( and keep the night temps up)?
How many more weeks to chop... you should probably check runoff ph too
 
Eastwind

Eastwind

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How many more weeks to chop... you should probably check runoff ph too

This is my first grow. I'm am thinking 3 to 4 weeks to go...by the look of the buds under a scope...now maybe 20% brown hairs & still clear Tri's. Will def check runnoff PH.
 
Eastwind

Eastwind

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How many more weeks to chop... you should probably check runoff ph too
Checked the runoff today....its still at 6.5. I gave them all a good flush, with about 20% runoff out to the tray....just in case there is some salt buildup in the pots. We have had some cold nights here. When the timer goes off...it shuts down the lights and fans...so cold air may travel in thru the vent window( that runs to the outside). Now I put a piece of foam insulation in there at lights out to cut down on the cold air blowback at night.
 
GT21

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Checked the runoff today....its still at 6.5. I gave them all a good flush, with about 20% runoff out to the tray....just in case there is some salt buildup in the pots. We have had some cold nights here. When the timer goes off...it shuts down the lights and fans...so cold air may travel in thru the vent window( that runs to the outside). Now I put a piece of foam insulation in there at lights out to cut down on the cold air blowback at night.
Its probably the cold air if your run off is there... it cooled down the roots
 
NightsWatch

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If your ph is same as its coming out then your plants are hungry i say bump up feed possibly add some veg nutes into the equation
 
NightsWatch

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Veg nutes only a couple weeks from flush? .. i would guess pk
veg nutes from start to finish plus bloom boosters fulvix and vitamins in flower equals healthy plants from start to finish
I have done it that way for years with great results just slowly lower veg nutes but still even feed last week light dosage
 
GT21

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veg nutes from start to finish plus bloom boosters in flower equals healthy plants from start to finish
I have done it that way for years with great results just slowly lower veg nutes but still even feed last week light dosage
Interesting. .. im not a big fan of excess nitrogen
 
NightsWatch

NightsWatch

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i wish more people would try it even on a few plants lets face it what do most people incounter 2- 3 rd week of flower Deficiencies
its a given.
But by giving them veg nutes and bloom nutes through out flower of course at lower dosages as you flower it allows plants to be less stressed and produce its a win win
 
NightsWatch

NightsWatch

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No shit GT try it what happens is people flip to flower and stop using veg nutes forst 2 weeks on 12 / 12 plant is using up all te Nitrogen TBH its still in veg / strech phase by 3rd week N is used all up and what bloom nutes have for N is not enough

Please try it you will be in WOW factor specially needed in tree grows
PPP
4 pound
 
GT21

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No shit GT try it what happens is people flip to flower and stop using veg nutes forst 2 weeks on 12 / 12 plant is using up all te Nitrogen TBH its still in veg / strech phase by 3rd week N is used all up and what bloom nutes have for N is not enough

Please try it you will be in WOW factor specially needed in tree grows View attachment 647224 View attachment 647225
Looks great bud.. my bud pumped too much nitrogen this year and wasnt impressed with frost or taste... the reason OPs plant is showing p- is because it was a little extreme in temp drop and it lowered the electric conductivity of the roots
 
2016 11 20 141015
NightsWatch

NightsWatch

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I agree cold ambient temps can cause p issues but when we look at thermal mass in general in soil @ feet depth in relation to outside temperatures we soon find about 8 - 9 degree warmer per foot depth but this is in actual earth 24 hr period

GT Trend1 Day


Being this is grown indoor and during 12 hrs of lights off
lets keep in mind below grade surfaces are surrounded by soil not air..

The conductivity of soil varies with soil types and moisture content.
But on average its 40 - 50 times more conductive then air.
Actually i am going to start a thread on heat loss and how to calculate it who knows maybe be a pinned thread
GT Trend1 Day
 
Eastwind

Eastwind

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I agree cold ambient temps can cause p issues but when we look at thermal mass in general in soil @ feet depth in relation to outside temperatures we soon find about 8 - 9 degree warmer per foot depth but this is in actual earth 24 hr period

View attachment 647242

Being this is grown indoor and during 12 hrs of lights off
lets keep in mind below grade surfaces are surrounded by soil not air..

The conductivity of soil varies with soil types and moisture content.
But on average its 40 - 50 times more conductive then air.
Actually i am going to start a thread on heat loss and how to calculate it who knows maybe be a pinned thread View attachment 647242

A big thanks to GT and NightsWatch for your input. I appreciate you takin' the time with a beginner. My grow room is in a basement, so below ground level....with my fresh air vent a basement window. Once the timer trips the lights and fans at 10PM...it was easy for the cold night air to creep in and settle down to floor level...where the girls are. My Bloom feed is a 3-12-6...after todays good flush..I'll keep an eye the next two days and see where things go.
 
mango420

mango420

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Couple things, temps are too low during lights on and WAY to low at lights out. Nighttime temps should stay in the low 70's and daytime mid to high 70's. Your plants are probably taking 6 out of the 12 hours of light to recover from being frozen. Also do not use super thrive in flower. It's for veg, and the whole vitamins thing for your plants is very overrated. What ppms are you feeding?
 
Eastwind

Eastwind

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Couple things, temps are too low during lights on and WAY to low at lights out. Nighttime temps should stay in the low 70's and daytime mid to high 70's. Your plants are probably taking 6 out of the 12 hours of light to recover from being frozen. Also do not use super thrive in flower. It's for veg, and the whole vitamins thing for your plants is very overrated. What ppms are you feeding?
Thanks for your input Mango. For measuring, I am just eyeballing with a 1/8 tsp measuring spoon...and going 1/2 to 3/4 recommended dose via the label. Don't know how to do PPM readings yet. Today I aerated the soil in the pots with a thin stick....the soil was still moist from 2 days ago's flush..so the cold is messing with the uptake ( it usually needs water by now). Also, last night I closed the vent window at lights out. That made a big difference today...I could feel it was much warmer...temps in the 70s. I will continue to do that because I think things will improve.
 
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