please help to ID deficiency

[plumbum]

hi icmag, it's been awhile. could you guys please help me to identify deficiency.

I am trying a new powder nutrient from Hydro-Gardens Chem-Gro 4-20-39 with coco/perlite mix (botanicare aeration). Plants look vibrant and healthy except the deficiency.

I've seen it before with other nutrients and other strains, but not sure what exactly the problem is. Usually i see it after plants are sitting in the dark for 30 hours to induce flower just at the flip from 18 to 12 hours. Thank you so much!



Is it magnesium? I wonder if too much potassium in 4-20-39 formula is interfering with magnesium uptake??

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How long has this problem been going on? - about a week

Are you growing in a PVC grow tent? (example: Hydrohut or any other non brand tents) - NO

What system are you running? (DWC? Ebb flow? Aero? Water Farm? Flood Tables? and so on...) - 3 Gal Smart Pots with Botanicare Aeration formula Drain to waist

What STRAIN are you growing? - Guerilla Glue #4

What was the establishing technique? (Were the seed or clone?) - Clones

What is the age of your plants? - 6 weeks after clone

How long have they been in there mixture they are in now?(coco,soiless etc..) - 4 weeks

How tall are the plants? - 2 feet

What PHASE are the plants in? (seedling, vegetative or flower) are the plants in? - Beginning of week 2 in flower

What Technique are you using?

What substrate/medium are you using?(Hydroton, RockWool etc.) - Botanicare Aeration formula - coco/perlite mix

What is the Water temperature? - 79F

What color are your roots? White? Brown? Are your roots slimy? - White
healthy

What Nutrient's are you using?(If growing soiless) - Pro-Silicate 0-0-4, Hydro-Gardens 4-20-39, CalNit, Magnesium Sulfate, Ful-Power, Hygrozyme

How much of each nutrient are you using with how much water?

Pro-Silicate 1.5ml/G
4-20-39 1.8 g/G
MgSO4 1.8 g/G
CalNit 1.8g/G
Flu-Power 10ml/G
Hygrozyme 5ml/G


Nitrogen N Total 93
Phosphorus P 41
Potassium K 175
Magnesium Mg 48
Sulfur S 61
Calcium Ca 90
Iron Fe 1.94980
Boron B 0.95112
Manganese Mn 1.04624
Zinc Zn 0.23778
Molybdenum Mo 0.04756
Sodium Na 0.00000
Copper Cu 0.23778
Chlorine Cl 0.00000
Cobalt Co 0.00000
Silicon Si 19.5614
Selenium Se 0.00000

Total EC 1.5
ph 6.2


How often are you feeding? (If using soiless) - Every other day

How often are you giving nutrients? (If using soiless) - Every feeding

If flowering, when did you switch over to using Bloom nutrients? - using Same nutrients in Veg and Flower

What order are you mixing your nutrients? (example: veg nutes 1st, bloom 2nd ect) - order listed - RO Water, Silicate, 4-20-39, MgSO4, CalNit, Ful-Power, Hygrozyme

What is the TDS/EC/PPM you are using - 1.5EC = 1050 ppm (700 scale)

What is the pH of the "Tank"? - 6.2

How often are you testing your pH/PPM/EC/TDS? - once a week

Are you sure your calibration is correct on your equipment? - yes

When was your last watering? - two days ago

What is your water temps? - 79F

When was your last feeding change? (ie. grow-bloom-micro-additional) about 10 days ago switched from Cutting Edge Solutions 3 part to Chem-Gro 4-20-39

How often do you clean your system: example: Flush out water replace with clean water and nutrients? - every feeding

What size bulb are you using? - 1000 DE Gavita

How old is the bulbs you are using? - 3 month

What is the distance to the canopy? - 5 feet

What is your RH Factor(Relative Humidity)? 55-60%

What is the canopy temperature? - 78-80F

What is the Day/Night Temp? (Include flucutaion range) - Same

What is the current Air Flow? (cfm etc.) - good air flow

Tell us about your ventilation, intake exhaust and when its running and not running ? - sealed system

Is the fan blowing directly at plants? - yes, but gently

Is your water HARD or SOFT? - Soft

What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water? - RO

If using tap water, what is the ppm/EC/TDS of the water right out of the tap? -N/A

If using RO,Distilled,mineral water, what is the ppm/EC/TDS without any additives? 4 ppm

Are you using water from a water softener? - NO

Has plant been recently pruned, cloned off of or pinched - NO

Have any pest chemicals been used? If so, What and When? - NO

Are plant's infected with pest's - I don't think so

 

[Speed of green]

You are feeding plenty of mag at 1.8g/G

The deficiency looks like N.

Something in the mix could be interfering with the N uptake. Maybe try just the calnit and your 4-20-30, foliar the mag and ful-power if you want, my plants love that.

The ph could be a couple points less but i doubt that is the issue.

There is a pretty good group of people on here (including me) that use jacks hydroponic 5-12-26 & calnit, im not saying to change nutrients but there is a lot of good info and people to help.

 

[Avenger]

Usually i see it after plants are sitting in the dark for 30 hours to induce flower just at the flip from 18 to 12 hours

WTF?

etoliation, look it up, stop causing it

 

[plumbum]

I need to correct myself. I've had a typo Hydro-Gardens Chem-Gro is 4-20-39 ( not 4-20-30). Here is the link:

https://hydro-gardens.com/product/420-hydroponic-25lbs-bag/

CHEM-GRO 4-20 HYDROPONIC FORMULA 4-20-39
GUARANTEED ANALYSIS
Total Nitrogen (N) ……………………………………………………4.00%
Nitrate Nitrogen…………………………………………3.50%
Ammoniacal Nitrogen………………………………….0.50%
Available Phosphoric Acid (P205)………………………………20.00%
Soluble Potash (K20)……………………………………………… 39.00%
Available Magnesium as (Mg)……………………………………..0.35%
TRACE ELEMENTS
Boron as (B) …………………………………………………………….0.20%
Copper as (Cu)………………………………………………………… 0.05%
Iron (Chelated) as (Fe).. ……………………………………………..0.41%
Manganese as (Mn)……………………………………………………0.22%
Molybdenum as (Mo) …………………………………………………0.01%
Zinc as (Zn)……………………………………………………………….0.05%


Speed of green, thank you for your advice. 4-20-39 has almost no magnesium - 0.35% which is only 2 ppm if i add 1.8 g/G , so all magnesium comes from me adding magnesium sulfate. at 1.8 g/G MgSO4 my magnesium level is at 48 ppm. When I've started, i've been giving plants 0.75 g/G = 21 ppm and it was too low. I've seen signs of magnesium deficiency so i had to go higher.

I am going to look into Nitrogen, but i always thought it is mobile deficiency and it effects lower leaves first.

Yes, i need to talk to growers who have experience with Jack's. After all its not that much different.

Avenger, I've been using 30 hours of darkness for a while and always saw positive effect - faster transition to flower. Leaves yellowing would happen on some strains and usually go away within a day or two. What i am seeing now is not caused by that. It happened a week ago and plants didn't experience yellowing.