Coco DTW, light green/yellow tips

[Mountainkush]

Hey everyone,
Hoping you guys can help me before I do anything stupid or anymore stupid things I guess.

I’m growing a Neville’s haze x panama(Ace) in a 3 gallon fabric pot of pure coco watered twice a day DTW with canna coco a&b.
Starting water is 0.2ec
The problem started around 3 weeks in my flower tent when I lowered the ec from 0.9 to 0.7 for a different plant fed from the same tank that had a bit of tip burn and a few leaf tips turned brighter green. They seemed kinda hungry so I started feed her from a different tank I was using that was at 1.1ec.
That went well for about a week before I noticed how dark the leaves had become and noticed a little tip burn on this one as well so I gave it a good flush with some Calimagic and canna coco a&b(water0.2ec/calimagic0.2/a&b0.4ec) then started back feeding at 0.8 a&b and no calimagic.
The flush was two days ago and here is how they look now. Water going in is 0.8ec 5.7ph and the runoff is 0.8ec 6.2ph. The tops look a nicer green colour but are turning yellow still.
Hoping for some advice before I try something else and mess them up even more.
I should add this is only at the top of the plant.

 

[TanzanianMagic]

Neville's Haze and Panama, or ACE's Panama Haze are pretty tall plants. My guess their height would be closer to 6 or more feet if left to grow without pruning.

At 1 gallon per foot, that would be 6 gallon pots. If you use bigger pots (and water less and use a lower nutrient concentration) then coco is also a very easy medium to transplant in, because it has no nutrients, so it can't burn the roots. Which is especially important during flowering.

Also, transplanting at this stage of flowering, and giving the plants the high P/K flowering food, will massively increase the number of bud sites and bud size.

 

[Mountainkush]

Neville's Haze and Panama, or ACE's Panama Haze are pretty tall plants. My guess their height would be closer to 6 or more feet if left to grow without pruning.

At 1 gallon per foot, that would be 6 gallon pots. If you use bigger pots (and water less and use a lower nutrient concentration) then coco is also a very easy medium to transplant in, because it has no nutrients, so it can't burn the roots. Which is especially important during flowering.

Also, transplanting at this stage of flowering, and giving the plants the high P/K flowering food, will massively increase the number of bud sites and bud size.

Thanks for the reply. Do you think the tips yellowing are from being root bound?
She’s around 36 inches from the top of the pot with a 4’x2’canopy and topped with 16 main colas. Didn’t get too out of control at almost 6week flower now.
I couldn’t imagine that being the case with everything I’ve read. Most people use smaller 1-2 gallon pots and water multiple times daily. I could try watering 3 times instead of 2 if you think maybe it’s getting too dry and locking out something. My first guess was copper might be locked out and hoped the flush would help that.

Also wondering if my Nute profile is off with the canna coco a&b and maybe that’s locking something out in the coco but without knowing what’s happening I don’t want to guess and change it too much. Was gonna try adding some Cannazym to raise the k higher than my calcium as I read that’s important but I wanted to get some opinion before I make anymore changes.

 

[TanzanianMagic]

Thanks for the reply. Do you think the tips yellowing are from being root bound?

If it was just a nutrient deficiency, would say:

- The upper leaves are most affected, and the leaf damage starts at the leaf tips, while the plant is very dark green, which is not healthy.

- Because the damage starts at the top, it is most likely from a non-mobile nutrient deficiency/lockout, like the trace elements, not NPK or Mg which are mobile.

- Of the trace elements Fe, Cu, Mo, Mn, B, it looks most like a copper deficiency, because the damage starts at the tips of the leaves. Iron deficiency starts at the center of the leaves and moves outward. They can get locked out at a high pH, however 6.2 shouldn't present a lot of problems. In coco 6.0 pH is a good pH to aim for until flushing, which should be lower to increase micronutrient absorbtion. (However, if you feed 5.7 pH and the runoff is 6.2 pH, the actual pH of the medium might be higher. So it is still possible that the pH is too high.)

This is the image I could find that is most like it.

https://wegrowapp.com/wp-content/up...iency-yellow-tips-leaves_jpg__1200×900_-1.png

https://wegrowapp.com/nutrient-deficiency/

 

[Mountainkush]

That’s exactly what I was thinking. Looks like copper and the ph is too high in the medium.

I flushed it at 5.8 ph but stupidly didn’t check the run off ph, only checked the ec to make sure it was back on track after the higher feeds.
Then, Seeing the ph at 6.2 coming out I lowered the feed to 5.7. But after I couple days of watering it hasn’t changed at all.
Maybe I should give a good flush again without the calimagic at a lower ph maybe 5.5 until I see a change in the runoff.

I think flushing with the calimagic in the water was a mistake. So much conflicting information about coco on the internet, it’s hard to tell what to do sometimes. Especially about what to feed when and at what ph.

 

[TanzanianMagic]

Also "water0.2ec" - that's a very low EC for water, almost soft water.

It would need a micro-nutrient solution like GHE's B'Essentials. Or put a teaspoon of maerl into a quart of water for a day or two, filter and add 3 quarts of tapwater.

Not a lot, just to compensate for the minerals that aren't in the water.

 

[Mountainkush]

Thanks for taking the time to help out.
Maybe I should stop adding my filtered water with 0.0ec. Ive been mixing my rez with 14gallons 0.3ec with 7gallons 0.0ec so I didn’t need as much phosphoric acid to bring my ph down.
I’ve been wondering if maybe it’s just being over fed and maybe too much wind and too dry. Temps are 25-26C with 45-50%rh and lots of air circulation. The VPD is a little off.
I raised my lights and fans just in case.

Also considered that maybe this plant just needs lots of copper or whatever is missing/locked out because my Zamaldelica x panama(same panama mother) beside it is on the same feed with same ph runoff and looks great.

I’ll try to look into the things you mentioned a little more or something similar as not much came up to buy online here in Canada.

 

[Vash]

Looks like a little overfeeding to me. Burned tips. I'd check runoff. If your water is only .3ec, that's ok. I wouldn't make it any more complicated. Keep it simple. My water is the same ec as yours, and I have no issues. Good luck.

 

[@hempy]

Sativas can be fussy some can handle full feeding all the way to the end other sats from a few weeks into flower only want 1/2 strength feeds some may only need water from early into flower till the finish.With hybrid sats you need dial each plant in let it tell you what it wants Nevs can be 1/2 strength feeds from early into flower.



I would also only water them once a day but if the medium is drying then water twice a day but if it remains moist feed only once as coco retains a lot of moisture.

 

[brickweeder]

I tend to agree with vash, looks like nute burn to me due to the really dark leaves in concert with the tip burn and the timing coinciding with your feed change to 1.1 ec. The damage was probably done shortly after you moved up to 1.1, and it just took a bit to manifest. Pay attention to the new leaves now that you scaled the ec back.

 

[Mountainkush]

Looks like a little overfeeding to me. Burned tips. I'd check runoff. If your water is only .3ec, that's ok. I wouldn't make it any more complicated. Keep it simple. My water is the same ec as yours, and I have no issues. Good luck.

Thanks vash. That’s what makes the most sense to me at the moment and what I started trying to fix yesterday. I mixed up a third rez for just this plant at 0.5ec so only 0.2ec Canada coco a&b added and will see how they react.

 

[Mountainkush]

Sativas can be fussy some can handle full feeding all the way to the end other sats from a few weeks into flower only want 1/2 strength feeds some may only need water from early into flower till the finish.With hybrid sats you need dial each plant in let it tell you what it wants Nevs can be 1/2 strength feeds from early into flower.



I would also only water them once a day but if the medium is drying then water twice a day but if it remains moist feed only once as coco retains a lot of moisture.

Thanks hempy

I’ve grown a few Sativas but not many like this one. I had an Ace Tikal that grew similar and went 16 weeks that was a finicky eater. Funny, I just realized that was a nl/haze hybrid as well but with different Central America Sativa.
It’s definitely harder than I thought to grow multiple different strains on the same feed. Wishful think maybe.
The pot gets pretty light after 6 hours which is when I give the second feed so I’d be worried to let them go the whole day on one feed. I’d be worried about salt buildup.

 

[Mountainkush]

I tend to agree with vash, looks like nute burn to me due to the really dark leaves in concert with the tip burn and the timing coinciding with your feed change to 1.1 ec. The damage was probably done shortly after you moved up to 1.1, and it just took a bit to manifest. Pay attention to the new leaves now that you scaled the ec back.

Thank you brickweeder
That’s the same thought I had a couple days ago and hopefully things with turn around soon. I’ve seen my tips burn before but never turn light green or yellow first. That’s why I though it was missing something and not that I had too much.
I’m hoping now that I lowered the feed it won’t look much worse tonight when the lights come on. We’ll see.

 

[RB56]

Is the coir drying out between feedings? Easy to get tip burn at low EC if the medium dries out.

 

[Vash]

As brickweeder stated, the dark green leaves were a tipoff as well. That usually means an excess in nitrogen. Sativas are a different ballgame when feeding. You have to back off and feed lightly, as you are discovering now. You"ll be okay

 

[Mountainkush]

Is the coir drying out between feedings? Easy to get tip burn at low EC if the medium dries out.

Hey RB56,
The pots get lighter between waterings but not dry at all. I only let them dry out(not completely)after I’ve transplanted to let the roots search for water.

 

[Mountainkush]

As brickweeder stated, the dark green leaves were a tipoff as well. That usually means an excess in nitrogen. Sativas are a different ballgame when feeding. You have to back off and feed lightly, as you are discovering now. You"ll be okay

Hey Vash,
I probably should of known but the tips yellowing made me think deficiency and when I saw copper caused that along with dark blueish shiny leaves, it made sense at the time. Live and learn. I kept a cut so if I mess it up too bad and it seems special I’ll try again.

 

[brickweeder]

I hope it turns around soon. As a side note, I ran into some issues on a soil grow, and it is much more difficult to ID probs and implement solutions in soil...and it is painfully slow. With hydro, a few days may seem like no progress is being made, but if you were in soil, you might have to wait 2 weeks before you start to see signs of progress.

 

[Mountainkush]

I hope it turns around soon. As a side note, I ran into some issues on a soil grow, and it is much more difficult to ID probs and implement solutions in soil...and it is painfully slow. With hydro, a few days may seem like no progress is being made, but if you were in soil, you might have to wait 2 weeks before you start to see signs of progress.

So far so good. It’s not getting any worse and she continues to flower so that makes me happy.