Deficiency, lockout or nute burn?

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Okj

Okj

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📍7 week old autoflower (still no signs of sex)
📍30/30/30 peat/perlite/soil repotted from 3gal to 6gal 50/50 peat/perlite
📍Watered when dry with 6.5 pH'd DC tap water ~130-150ppm
📍Fed with 400ppm 24-13-13 NPK mineral fertilizer for 2-4 weeks, from week 5 bumped to 700-800-900ppm 20-20-20 +micro mineral fertilizer.Note that almost every watering was feeding.
📍Last week started to feed 300-400ppm of only calcium nitrate + magnesium sulfate 3:1 ratio(since it's very dark green from excess Nitrogen). Until week 6 i did not feed with CalMag.
📍 Repotted because i think it's photoperiod(week 7 and no signs of sex) and roots were coming out of the bottom of fabric pot.
Will be glad and thankful to receive some input from experienced growers
 
ezenzyme

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Its def not burn or lock out, burn is on the tips of the new growth yellow to brown starting at the upper part of the plant. Lockout is when your plants look hungry but cannot uptake the food your feeding. Whats the NPK of your current feed? How much water and how often? Do you have a PH meter? pics of the entire plant would give a better idea of whats going on, stuff can start on the bottom or the top and that can be the sign to dictate the proper diagnosis
 
Okj

Okj

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Its def not burn or lock out, burn is on the tips of the new growth yellow to brown starting at the upper part of the plant. Lockout is when your plants look hungry but cannot uptake the food your feeding. Whats the NPK of your current feed? How much water and how often? Do you have a PH meter? pics of the entire plant would give a better idea of whats going on, stuff can start on the bottom or the top and that can be the sign to dictate the proper diagnosis
Last 4 or 5 waterings were only 300-400ppm(130-140ppm comes from tap) of CalMag(Calcium nitrate plus Magnesium Sulfate 3:1 elemental ratio. I dissolve them separately and then mix A sol. Shake mix B shake to prevent cal precipitation.)
Yes i always pH at 6.5(+or - 0.1)and calibrate it every week,stored in storing solution.
I weighted pots fully dry and fully saturated so i weight and water when its almost bone dry.
New little fresh shoots near had dark blackish necrosis. Fan leaves had rusty spots and burnt edges and tips.
 
Aqua Man

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That's a crazy amount of nitrogen... your ratios are way way way out... and definitely causing root and uptake issues..... in the proper ratios 100-120ppm of nitrates. You cal mag may even be an ammonium sourced nitrogen which is about 4x stronger than nitrate nitrogen.

I will also assume the PH is not in a good place given the ratios.

flush the plant very well with an enzymes preferably. 3x the pot volume

Between the ferts you have use the 20-20-20 about 400ppm to feed after the flush. You will want to do this right after the flush.

The plant maybe pissy for a few days and damage will not go away... affected leaves will get worse and die. New growth should improve in 3-5 days.

Reduce the light intensity by 25-50% for that period.
 
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Moshmen

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That's a crazy amount of nitrogen... your ratios are way way way out... and definitely causing root and uptake issues..... in the proper ratios 100-120ppm of nitrates. You cal mag may even be an ammonium sourced nitrogen which is about 4x stronger than nitrate nitrogen.

I will also assume the PH is not in a good place given the ratios.

flush the plant very well with an enzymes preferably. 3x the pot volume

Between the ferts you have use the 20-20-20 about 400ppm to feed after the flush. You will want to do this right after the flush.

The plant maybe pissy for a few days and damage will not go away... affected leaves will get worse and die. New growth should improve in 3-5 days.

Reduce the light intensity by 25-50% for that period.
So do you think the nitro/cal is locking out the mag?
 
Aqua Man

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So do you think the nitro/cal is locking out the mag?
No need for cal mag with tap... maybe mag sulfate but no need for calcium.

And yes high nitrogen will increase demand for magnesium, reduce availability of K that really can affect uptake and transportation of water.
 
Aqua Man

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To boot excess Ca will also reduce availability of P, K and mag.... nevermind micros.
 
Moshmen

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No need for cal mag with tap... maybe mag sulfate but no need for calcium.

And yes high nitrogen will increase demand for magnesium, reduce availability of K that really can affect uptake and transportation of water.
Yeah that tap water thing really messed me up when I began I tried rainwater , blah blah blah- ended up with a gallon of calmag I haven’t opened in well prolly a year . Lol
Thanx
Mosh
 
Okj

Okj

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That's a crazy amount of nitrogen... your ratios are way way way out... and definitely causing root and uptake issues..... in the proper ratios 100-120ppm of nitrates. You cal mag may even be an ammonium sourced nitrogen which is about 4x stronger than nitrate nitrogen.

I will also assume the PH is not in a good place given the ratios.

flush the plant very well with an enzymes preferably. 3x the pot volume

Between the ferts you have use the 20-20-20 about 400ppm to feed after the flush. You will want to do this right after the flush.

The plant maybe pissy for a few days and damage will not go away... affected leaves will get worse and die. New growth should improve in 3-5 days.

Reduce the light intensity by 25-50% for that period.
Thanks for the reply aqua.
As i know ammonium sourced calcium does not exist.
Calcium nitrate is the only available calcium source from mineral fertilisers. All branded CalMag fertilisers use it like : GHE calimagic, Botanicare Calmag plus, Advanced Nutrients Sensi CalMag and etc.. Also their Magnesium comes from magnesium nitrate(in every concentrate liquid formulas where Cal nad Mag are together both are in nitrate forms) . So i opted for mag sulphate(epsom salts) not to overdo nitrates.
In NPK dry ferts numbers are high becuase they are simply dry , just needs to be diluted to desired ppms. 20-20-20 is 20-8.7-16.6 in elemental form , manufacturers use oxide forms of P K . Multiply P% by 0.436 and K by 0.83 to get pure elemental ratios.
Why is pH not in a good place ,though?
What ratios of NPK(please mention elemental or oxdie form) do you recommend for veg and flower for autoflowers. At what ppm should i feed and should i feed every watering or every other watering .
 
Okj

Okj

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No need for cal mag with tap... maybe mag sulfate but no need for calcium.

And yes high nitrogen will increase demand for magnesium, reduce availability of K that really can affect uptake and transportation of water.
Before i used calmag plant's growth was stunted,developed rusty spots and burnt tips, new growth necrosis.
After i used CalMag it responded pretty good , resumed to grow and new growth was healthy.
Idk whats in my tap water of 140 ppm, also i don't exclude it from total ppm. It comes @7.45 ph and when i pH down it with dry citric acid to 6.5ph ppm drops about 20-30 units, i guess some neutral isation happens.
What pure form of K do you recommend. I have muriate of potash(KCl)0-0-61 but i have not used it yet. Does cannabis tolerate chlorine from KCl?
 
Aqua Man

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Before i used calmag plant's growth was stintes,developed rusty spots and burnt tips, new growth necrosis.
After i used CalMag it respondes pretty good , resumed to grow and new growth was healthy.
Idk whats in my tap water of 140 ppm, also i don't exclude it from total ppm. It comes @7.45 ph and when i pH down it woth cirtic acid to 6.5ph ppm drops about 20-30 units, o guess some neitralisation happens.
What pure form of K do you recommend. I have muriate of potash(KCl)0-0-61 but i have not used it yet. Does cannabis tolerate chlorine from KCl?
Do not use KCL.

Your local water report will show the makeup and 50-80% of that ppm will likely be caco3

Citric acid is NOT good to use and is not needed in a buffered soil where alkalinity is reasonable.
 
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Aqua Man

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You don't need more K you need proper ratios.
 
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Aqua Man

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If you look at the total nitrogen on your cal mag then look at the nitrate nitrogen. I'm betting you see 2 different numbers no? I could be wrong not all cal mag contain ammonium
 
Aqua Man

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I see. You wrote only ammonium so i thought pure CaAmmonium.
Mine is pure CaNitrate from YaraLiva Calcinit 15.5N of Nitrate-N and 19% pure Ca
I mean in the cal mag... its a very small percentage but usually it's there.
 
Aqua Man

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The citric acid will react with bicarbonate in your tap water to create carbonic acid and off gas as co2 very quickly... so it's not a good ph buffer unless your just using it for the ph when mixing to prevent precipitate. Other than that you don't need a PH adjust in a buffered mix like almost all peat it these days.
 
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