What is the deficiency? (pics)

Hello,

These are root cuttings, freshly, put into large pots. They're all giving this same problem. Rust coloured, decayed leaves, new leaves with little chlorophyll (pale).

Substratum: coconut
Fertilizer: Canna coco
PH: 5.9 / 6.0
Light: 18/6 - Led
Temp. Maximum 25 min 20
Humidity: 40% - 50%.













What could be happening?

When were they transplanted? Into how large of pots? Did you prepare the coco at all? What did you feed them? Tap water or RO? EC of feeding? Looks like they’re locked out. Are they drinking or are the pots overly saturated?

PurplePotion said:

When were they transplanted? Into how large of pots? Did you prepare the coco at all? What did you feed them? Tap water or RO? EC of feeding? Looks like they’re locked out. Are they drinking or are the pots overly saturated?

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Transplanted one a week ago to 3 liter pots.

The coconut comes ready, it's canna coco professional sack. (Bought in grow shop).

I am feeding with canna coco, according to the manufacturer's instructions (4ml/l).

Tap water, wiouth cloro, idont know ec. The substrate is drying out normally, so I think they're drinking.

superhaze420 said:

The substrate is drying out normally, so I think they're drinking.

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Coco isn't supposed to dry out like soil ...it's sort of a hydro medium. You're supposed to keep coco atleast somewhat moist all the time.

So i think you're unerwatering them and there's prolly some lock outs because of this ..flush the medium well with mild nute solution and start watering them more.


I don't grow in coco, did one run by hand watering some years ago, so i hope proper coco growers will chime in. ..or maybe you should visit the coco-forum here and ask someone to help you.

..but in short, don't treat coco like soil.

Too cold too dry.

Also, many times cannabis doesn't need as much nutrients as nute manufactures imply in their feeding charts. I use BioBizz nutrients myself in soil and many plants i grow will do fine at around 50% of what BioBizz claims. ..plants like C99, BlueBerry, Black Domina, Cheese and so on.
But i'm not familiar with the brand you're using, so better ask a second opinion from someone else. Just saying.

Mr. J said:

Too cold too dry.

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Can’t help but agree with this guy. Humidity definitely needs to come up. Also, make sure you’re getting at least 20-30% run off until things straighten out.

By chance.. You aren’t letting them soak up the run off are you?

Coco is an inert media. Treat it like hydro. Would you leave your DWC in stagnant water for long periods?

I water my coco every day.

if we really dont know,, than good rule is aplicating nutrients straight on the leafs,, ohh good luck

superhaze420 said:

Hello,

These are root cuttings, freshly, put into large pots. They're all giving this same problem. Rust coloured, decayed leaves, new leaves with little chlorophyll (pale).

Substratum: coconut
Fertilizer: Canna coco
PH: 5.9 / 6.0
Light: 18/6 - Led
Temp. Maximum 25 min 20
Humidity: 40% - 50%.



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What could be happening?

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That's potassium deficiency.

After repotting, it helps to give the plants high P/K nutrients with a little magnesium or Epsom Salt.

For instance. 0.4 EC of high P/K (Plagron Green Sensation, Atami B'Cuzz Blossom Builder or Bloombastic, Canna PK 13/14), and 0.1 EC of epsom salt (MgSO4).

What the plant needs after transplanting is P for more root growth and K for strong stems. Mg helps the creation of chlorophyl, which is what makes the leaves fresh and green looking and phototropic.

--

Why is this potassium deficiency?

1. It's a mobile deficiency, starting at the large leaves and moving up node by node. Mobile nutrients are NPK and Mg. Non-mobile nutrients are Ca, S, Si and Trace Elements.

2. Serrated edge damage to the leaf; the leaf tips are also affected. This is characteristic for K deficiency vs. N, P or Mg.

https://www.marijuana-seeds.nl/blog/potassium-deficiency-in-marijuana

Heres my take OP. First of all it may be just the clone being a little roughed up and acclimatizing, it has only been a week. Especially if it came from high humidity. But from my experience 4 ml of A&B is WAY high for veg esp if you are letting the coco get dry (and many cases for flower too). Buy an EC meter, check your EC, check your runoff EC, do a slurry test of the coco. Feed 2 ml/L and ease off on PH down IMO because you are just adding unnecessary amounts of phosphate. 6.2 to 6.5 is fine for me, YMMV of course. My dedicated veg gets 6.5PH in 100% coco since over a year and 25% of the time I just use plain water 7.3 PH. My veg recipe with tap water is 2 ml/l A&B and 0.1 ml/l PH down. If that doesn't veg healthy plants, there is a big chance that something else is the problem. I'm not saying 6.5 is the best PH (especially not with a big reservoir) but using less PH down has not changed my veg.

Your medium can lock out because drying out makes the salts build up. It's not that big a problem if you are feeding low EC but you are feeding like 2.6 EC, so you should either keep it moist all the time to prevent EC rise, or reduce feed. And btw even if you watered it 24/7 4ml/l still can screw up plants that are "light feeders" so to speak. Yes you can let coco dry out, I do a wet/dry cycle coco in veg to prevent algae, fungus gnats and to also keep the springtail population in check.

I would not add a PK product on top of max dose A&B, it should already have potassium out the wazoo :O. I don't think being in a 20C-25C range will ever make a plants look that fucked up. 40% is a bit low but similarly 40% should not make it look that fucked up. Lots of healthy plants have been grown in 40% RH sodium rooms