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90 watts per sqf + CO2 identify defs with pics

erwingruber

Member
Hello everyone , I have several years of growing under my belt with good results .
Recently I boost my growroom with CO2 and more watts per square foot .
As I describe above plants growing under 90 watts/sqf with CO2 supplementation
@ 800 ppm CO2 early veg , @ 1200 ppm CO2 late veg and flower lowered after week 6-8 depending on strain .
As long as I stay @ 800 ppm of CO2 even the complete flowering stage no defs appear but I do not get that explosive growth of 1200 ppm .
When I induce 1200 ppm my feeding recipe appears to missing something even if I Rocket sky the EC of my solution to the point of severe nutrient burn .
The deficiency is always the same in a couple or runs and in a couple of strains.
(look at pics below) Begins with brown spot’s in the leafs , followed by yellowing to complete death of the leaf.

Although harvest’s weights remain remarkable @ 1200 ppm with the defiances I know I need to fix this .

Plants defiances look to respond good with CalMg foliar feeding in veg put I cannot foliar feed at flowering .
I’am growing in Hempy’s and I was thinking about ph lockout cause even if I am watering
With ph @ 5,2 in veg runoff comes out @ 7,1 tommorow I will measure flowering runoff but it not meant to measure runoff in Hempy’s .

Any ideas from CO2 experienced growers will be very very helpful :)
[FONT=&quot]Below you can see pics from different stages


picture.php
[/FONT]
 

Andyo

Active member
Veteran
what make of nutes

what make of nutes

what make of nutes.
And are your hempys using perlite
And whats your water source?
 

erwingruber

Member
@Andyo

GH 3 part as base nutrient , mixing as needed per stage ,
from 1-1-1 to 3-8-16 to 0-8-16 to 0-6-20 and blah… blah…
depending of my and plants needs ( If want to feed the stretch or to speed up the chopping etc )
Advanced Nutrients additivies and boosters , not in the run the photos came from.

Yeap perlite vermiculite 75% perlite 25% vermiculite
Tap Hard Water ranging @ 210 – 230 ppm

@Boyd
i think that mites will envade the complete grow at sometime , i encounter this defs regulary and i harvest with out seeing mites .
If it is not clear in my first post this not an issue that i encounter for first time i encounter this defs in 2 cycles veg+flowering . I run two more cycles @ 800 ppm CO2 with lighter nutes with no problems
an on this run i run @ 1200 ppm CO2 again and the defs apperar again . If it was mites , without treatment i believe that i will spot them sooner or later
i check Regulary and i am in a sealed enviroment but i will check again for mites.
 
Last edited:

Douglas.Curtis

Autistic Diplomat in Training
Russet are extremely tiny. Twisting leaves is a good first sign, a powdery rust on stems is actually thousands of mites. They don't do the normal webbing thing.
 

Ogtg2213

Member
That's an outrageous amount of light per sq foot, possibly to much depending on your light distance.
Combine that with 1200ppm co2 It could be simply pushing them to hard and to fast for what your root zone can provide, you may not be deficient in anything at all.

I experienced this before when growing in dirt, but in hydro I havnt had the issue. Same room, same nutes ect. So that's what I chalked it up to be

Could also be the ph swings,while pushing them that hard, but again that's just the rootzone being the weakest link.

Maybe try a few different soil mixes next time to see if more or less perlite/coco balances the ph and or wet n dry cycles

Or if possible try a small hydro setup if your hell bent on getting that explosive growth. That would put you one step closer to what it sounds like your trying to achieve anyways. And your nutrients would be readily available when you crank up the co2
 

Andyo

Active member
Veteran
Ammonium nitrate Nh4 v calcium nitrate NH3

Ammonium nitrate Nh4 v calcium nitrate NH3

As positive ions such as cations Ca2+, K+, Mg2+ are removed from the solution, hydrogen ions (H+) are released from the root system to equalize the ratio of anions to cations in the root zone and this lowers the pH of the solution.

When the crop begins an active growth phase, anions such as NO3 are taken up, which increases the pH through the release of hydroxyl ions (OH-) into solution.

The above is the cause of ph rise.
your perlite/vermiculite in the hempy pot is still rising after the flush at 7.1 most likley 7.5 +

I had this when i first used hydroton same in rockwool cubes.even using soft water.

The answer was swap 5% ammonium nitrate for 5% of calcium nitrate to my nutrient
I could do this because i have a nute formula which is a 2 part copy of ionic.
As ammonium nitrate is licensed and likley to get you busted by trying to order it/ you can use ammonium sulphate and
urea prills will work to a point.

General hydroponics had a dry PH down formulated from ammonium sulphate /urea and citric acid (NOT phosphoric acid)
Im not sure if its still availble but this would work in your case if you use RO water or Soft water

Formula is Ingredients:
pH Down
TM
Dry Concentrate contains ammonium sulfate, citric acid, and urea phosphate.
The exact concentration of
each chemical ingredient is a trade secret. A
 

mushroombrew

Active member
Veteran
Way more light than necessary. What type of lighting? Bulb?

How big is your grow? Adequate ventilation?

How do you measure pH? Do you calibrate often?

Use chunky perlite if you didn't. Small perlite with vermiculite can get really soggy.
I run RW croutons and chunky perlite. Works amazing.

pH should drift up a little but that seems like a lot. I would guess some root die off/decay. Can I get a pic of your roots please?

Like @ Andyo said using more NO3 vs NH4 can help. But check those roots first.
 

Douglas.Curtis

Autistic Diplomat in Training
As positive ions such as cations Ca2+, K+, Mg2+ are removed from the solution, hydrogen ions (H+) are released from the root system to equalize the ratio of anions to cations in the root zone and this lowers the pH of the solution.

When the crop begins an active growth phase, anions such as NO3 are taken up, which increases the pH through the release of hydroxyl ions (OH-) into solution.
Interesting, I don't see this at all in DWC. The last 15 years, I've added GH Flora and the pH has gone down. (Great pH down) As the plants have absorbed the nutrients from the solution the pH has gone up. I add nutrients back when the pH has risen to 6.0'ish, depending on the situation for the plants. This drops the pH back to start. Lather, rinse repeat. Reservoir is topped off once a day with pure r/o.

I see pH drop when the nutrient strength is too hot and I'm killing roots. The rot drops pH like a stone. ;)
 

Andyo

Active member
Veteran
more NH 4

more NH 4

Way more light than necessary. What type of lighting? Bulb?

How big is your grow? Adequate ventilation?

How do you measure pH? Do you calibrate often?

Use chunky perlite if you didn't. Small perlite with vermiculite can get really soggy.
I run RW croutons and chunky perlite. Works amazing.

pH should drift up a little but that seems like a lot. I would guess some root die off/decay. Can I get a pic of your roots please?

Like @ Andyo said using more NO3 vs NH4 can help. But check those roots first.

That should be use more NH4 to resist PH rise.A

And yes dump the soggy vermiculite!
 

troutman

Seed Whore
I would back off to 75 watts per sq. ft..

Like a racing car I think you're about to blow your engine.

Slow down and your plants will live longer.
 

Douglas.Curtis

Autistic Diplomat in Training
That should be use more NH4 to resist PH rise.A
Resist the pH rise?
Cannabis shines with a slow and steady pH rise/drop through the healthy pH ranges. You want a slow rise or drop, where rise is easiest with most nute profiles. The plants evolved in a changing pH environment, where each element became stored up and then used in cycles. Allowing the natural pH rise and fall, with the removal and addition of nutrients, really works with cannabis to produce a quality product. When nutrients sit around in the plant, cannabis locks it into new cell grows where it will never flush/fade out.

You want zero deficiencies? Gotta keep stuff moving. ;)
 

erwingruber

Member
@ Douglas

Thanks i will search more information for this anf i will check my plants with a microscope !

@ Ogtg

I begin to believe that this is the case and i did not even think of it , they veg 4 weeks in 3 gallon pots and straight to 12/12 .

There is no ph swings i feed with 10 gallons 5,2 phed water and the runoff swings from 7,3 to 7,1 . I think that maybe vermiculite brings the ph up . I cannot even imagine trying to bring the ph doen to 5,2 with flushing cause i think i must flush every 3 gallon pot with 100 gallons of water .

Hempy's not ment to measure runoff , at some point i will try a small RDWC that i have from the past but the plant count is big and i cannot switch to Hydro , i think that it is to much work and to many variables. In hempy's even with this issues dry weights is awesome .

@ Andyo

Andyo i am happy that you are here i know that guys like you finaly they find the solution .
Take note the above that i mention to Ogtg . No matter how much water i feed the 3 gallon pots they refuse to give me a runoff of 5.2 or at least 5.8 . I flush 3 gallon pot with 10+ gallons of 5,2 phed water and the runoff still comes out at 7,1 .

Today i fed the flowering plants with 1 gallon 5,6 phed water @ 1,5 EC and i took runoff 6,8 @ 1,8 EC . Hempy's is a headache if you try to treat them like Hydro.

I will try to find PH down formulated from ammonium sulphate /urea and citric acid .
keep checking me around .

With what you will suggest to replace the vermiculite ? Coco ?


@ mushroombrew

Yes it is a bit overkill and i keep them close to canopy
Canopy is 62 sqf (2,4 x 2,4 meters) and above they hang 9 600W HPS
Aircircualtion is ok and with the 2 ton AC i keep temps at canopy from 80F to 93F (even lower if i want it ).When i push the CO2 @ 1200ppm i usualy keep the canopy around 87F - 90F
Unfortunatly chunky perlite is not available anywhere near me neather RW croutons i think .

I measure with 2 different and calibrated digital phmeters .
ph not drifting up . imidiate runoff is what i measure


Thanks to all guys for trying to help , I will try for some pics from the flowering room
 

Andyo

Active member
Veteran
resist ph rise

resist ph rise

Resist the pH rise?
Cannabis shines with a slow and steady pH rise/drop through the healthy pH ranges. You want a slow rise or drop, where rise is easiest with most nute profiles. The plants evolved in a changing pH environment, where each element became stored up and then used in cycles. Allowing the natural pH rise and fall, with the removal and addition of nutrients, really works with cannabis to produce a quality product. When nutrients sit around in the plant, cannabis locks it into new cell grows where it will never flush/fade out.

You want zero deficiencies? Gotta keep stuff moving. ;)

This whole thread is due to excessive PH rise .IE over 7.5 in hempy buckets .
Personally i let my rez start at 5.8 and it will rise to 6.2 over 7 days
The hydroton run of drips taken at 1 hour and 2 hours after drain
will be 6.0 and 6.2 with a 5.8 rez and by the end of 7 days will be 6.2 and 6.3 1st and 2nd drips .A
 

mushroombrew

Active member
Veteran
OK small perlite/vermiculite = root problems.

You need something else. Hydroton, GS2, maybe coco cubes? Something bigger. I think your media is too soggy.

Fix that and your pH will likely normalize in your next run.
 

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